The following are some points I suggest a reader should note when reading Genesis in order to understand it and the rest of the Bible. It is copied from notes made and hopefully, will be re-written when time permits.

The name "Genesis" comes from a Greek word meaning "beginning." This word was the title of the book in the Septuagint, the ancient Greek translation of the Old Testament. The Hebrew name for Genesis was 'b rë shith', "in the beginning." The Hebrews often identified the books of the Old Testament by the first word of the text. In this way when a scroll was unrolled they were able to tell immediately which book it contained.

Aside from Genesis, there are no other writings that inform us of the events which predated Moses. The first part of the book describes the key events in the early history of man. The remainder of the book records the history of the patriarchs.

Genesis was written in a pre scientific age and was not meant to be a scientific document. Consequently, only divine inspiration can account for the perfect accuracy of its technical information. In Genesis, it is made clear that all things were designed and created by God and continue to operate within the boundaries of His purpose. Although the human race departed from God's original plan, God has lovingly provided a way for men to be reconciled to Him.

Though the Book of Genesis contains no express record as to who wrote the book, there are no logical reasons for denying that Moses is the author, not only of Genesis, but of all five books of the Pentateuch. The unity of the Pentateuch is attested to in various portions of the Old Testament, as well as in portions of the New Testament.
Even the opening phrase of the Book of Exodus, "Now these are the names," provides clear evidence to that unity. The Hebrew prefix that is translated "now" is the common form of the conjunction in Hebrew (most often translated "and" or "but") and indicates that there was some other book which preceded the Book of Exodus. Jesus refers to Moses as an author of Scripture in Luke 16:31; 24:44; and John 5:46, 47. ln John 7:23, the New Testament refers to circumcision as a part of the Law of Moses (see Gen. 17:12; Ex. 12:48; Lev. 12:3).

It has also been suggested that Moses made use of certain documents and oral traditions to write the book. Certain terms have been cited as proof of the previous authorship of certain portions. For instance, the term 'tol dôth' (8435) generations, is said to be used to identify the author or the possessor of certain portions (Gen. 6:9, 11:27). The "looking over" or "familiarity with" other writings is not unheard of among the biblical writers, nor is it contrary to biblical inspiration (see Luke 1:1 -4). However, it must be remembered that the actual writing of the Book of Genesis was done by Moses, under the inspiration of the Holy Spirit.

The Book of Genesis is an appropriate introduction to the entire Bible. It provides answers for the universal questions of the origin of all living things, the universe, sin, and evil in the world. More than half of human history is covered in its fifty chapters. However, the Book of Genesis is not merely the introductory book of the Pentateuch, but rather the foundation of it, of the whole Old Testament, yea of the whole of the Scriptures. Without the Book of Genesis, what would be known of the creation of the universe, the fall of man, the judgment of God, or the promise of redemption?
Since God is invisible, man may know of Him only through His works, which are seen in nature, revealed in Scripture, and accomplished in the life of the believer. And how deficient would our knowledge of God be without this book! Are not "his eternal power and Godhead" displayed in His creation (Ps. 19:1; Rom. 1:20)?

Yet the creation, in all that it portrays of the divine Creator, is not sufficient in its instruction to provide man with the knowledge necessary to attain salvation. At this point as well, however, the Book of Genesis lays the foundation of all the Scripture.
For the book is not limited to the account of creation, but rather emphasizes the fact that the world was founded by God, that man was created in righteousness and true holiness, but that man fell by his own disobedience, and therefore was cursed by God.
Furthermore, the first promise of a Redeemer, by whom the curse of death would be vanquished, is found in this book (Gen. 3:15, 16). The remainder of the Book of Genesis is in fact the first chapter of the history of redemption, in which God chose the seed of Abraham to be the line of the Messiah and the heirs of the promise (Gen. 12:1-3; Matt. 1:17; Gal. 3:6 -9, 29). [Source for Introduction of chapter: Hebrew Greek Key Study Bible KJV edited by Spiros Zodhiates, Th.D. AMG]

The following abbreviated notes are best understood when reading your bible and referring to the chapter and verse mentioned.  Earth’s human history is not 6000+ yrs as guessed by Archbishop Usher (i.e began 4004 B.c) He used Gen 5:11 to average life of generation).
Gen 1:5 sets start of day from evening to evening NOT midnight to mid night. This is repeated each day. Earth was made with life sustaining qualities before God made man. i.e He has order. Man made a living soul from breath of God being breathed into him (2:7). When man dies, body goes to earth, breath returns to God. 1:28 and 9:1 word replenish in Hebrew means “fill” not to indicate a previous human existence. Note 1:26 “began call on God”.

2:3 God blessed 7th day period of time denoted by evening to evening as set by sun and moon, sanctified it (made it holy and set apart from other days). Thus man cannot change this period of time around as is set by planets. Later in Heb 4:3-11 this 7th day is upheld as day of worship (see booklet Have I got it Right God). Previously covered directive God gave Adam and Eve in 2:16-17 and how satan misquote with bit of truth and lie. Adam died in the day he ate of tree (2Peter 3:8, God’s day = 1000 human years, Adam, Noah, Abraham all died before reached 1,000 (Gen 9:29)).  Forbidden one just test to see if will obey. Same as today.  We have other days to do as we will, 7th is test of obedience. Death is separation from God who gives life. Whether spiritual or physical. Adam and eve suffered spiritual death on the day they ate of the tree as they were put out of the garden, separated from God.
4:4 see 8:20, 13:18 ie Lev laws of sacrifice there before given to Moses. 4:13-14 Cain’s cry more of self- pity for punishment rather than remorse? Adam and Eve must have had more off spring as Cain afraid of other inhabitants. Either that or God made others; but chose Adam to put in the garden.
6:3 Man’s yrs reduced to average of 120. Note 6:5, Jos 24:15 the worse sin man can do, serve (acknowledge or worship) other Gods, idols, planets etc. as to why God punishes.
7:1, see Lev 11. Thus Lev laws before Moses, Israel etc i.e given to mankind.
7:11,12 Note Noah in ark for 1yr . See age he went in and came out (8:4,14). And despite all the signs, did not use his own judgement to come out; but waited on God to instruct him.
9:4 Not to eat anything with blood also repeated in Lev 17:10. 9:12.  Rainbow token of God’s covenant, same as circumcision in 17:11 with Abraham, same as Sabbath in Gen 2:3 with man kind.. 9:22 repeated in Lev 18:6.
10:5 “Gentile”. 1st time used = non God’s people. It is not a N.T word. And does not give person special dispensation to go against what God has set as qualification to become one of His people (Ex 12:40) (see booklet Have I got it Right God). Note what is dividing factors (tongue/language, family, nation). Hence speaking in tongues = another human language (see 11:1,7 all one language). 10:9 word “before = against” God. Nimrod is originator of pagan worship, the un Jehovah (ungodly).
12:1, 13:14, 15:18, 26:5 beginning of Exodus. 12:12 see 20:11
15:6 before he was circumcised and 400 yrs (Gen 15:13-14) before law given to Moses so neither circumcision or Law made Abraham righteous unless he was doing things of the law from the heart (Rom 2:14 For when the Gentiles, which have not the law, do by nature the things contained in the law, these, having not the law, are a law unto themselves: Rom 2:15 Which shew the work of the law written in their hearts”. See also 22:12 where Abraham willing to sacrifice ONLY son. And especially Gen 24:12 compared to Ex 24:12, 2Chron 19:10
Gen 15:10 see Lev 1:17 not divide birds. ,
Gen 16 birth of Ishmael linage (25:12) claimed by Muslims. (see 17:21,). 16:3-4 Notice sex with maid made her his wife.(also Gen 30) This also in Leviticus.
Gen 17:1 God’s blessings always conditional on doing His will/commandments. Promise to Abraham and His seed. Thus those wanting to be grafted into the promise and blessings must obviously keep the condition/terms on which blessing/promise given (see 18:19, 22:18).
17:14 see Ex 12:48.
Gen 19 Sodom and Gormorrah, even sons, sons in-law etc ungodly. Gen 20:3,11 Even heathen had adultery laws before Moses.
Gen 24:3 Abraham makes servant promise that Isaac his son would not marry Canaanite woman. Maybe because Abraham knew she may turn his heart onto their Gods. A commandment later repeated to Israel through Moses. I think it was Esau who married foreign women as knew displeased his dad (Gen 26:35, 29:8). Note Samson did same and Solomon. All went against God’s command not to mix marry. Note Num 25:3-11 and “unequally yoke” in N.T. ie believer with non believer not inter denomination as some think.
Gen 26:1-2 2nd part of beginning of Exodus. Did God cause Jacob to steal Isaac’s blessing so promise to Abraham would be fulfilled (played out). And all the other hints about younger son ruling elder Gen 25:23, 30:40, 31:9, 37:7, 43:28,39:20, 41:40 45:7 etc.
31:19,30,32 “images” of idol worship. Lot Abraham brother in pagan country following pagan practice that not even sons etc were saved. Laban same. Not following Jehovah God.. Fortunately Jacob did not succumb to their practice in the 20 yrs he lived among them (31:41, 54). But note 35:2. Did his household follow strange God’s because wife’s did i.e mix marriage? Note Egyptians did not mix with Hebrew Gen 43:42 nor wanted Hebrew inferior stuff to mix with theirs 45:20 hence they changed Daniel and friends names, clothing etc to names of meaning to their gods. ).
Gen 32:28, 35:10
Gen 38:8, 9, 26 Same rule given in Leviticus about taking dead brother's wife as yours and then inheritance passing from your sons to hers. Same reason why Ruth married Boaz rather than nearest kinsman. Thus God had his ways from before laws given to Moses to after.
Gen 39:9 (20:6) “Sin against God” not her husband.
Gen 41:8 pagan, gentiles, Egypt religion (satan’s) had magicians before Moses confronted Pharaoh. Thus satan’s workers can do miracles to deceive and “by this many shall be deceived even the very elect if it was possible”. Thus do not. necessarily follow miracle, healing etc churches.
Gen 46:26-7, Ex 1:1-5, Acts 7:14 sixty – 70 souls went in Egypt (too much to explain why different calculation). 47:11 note name Rameses as will re-occur later.
Gen 49:4 not sure if this to do with Gen 9:22 or another occasion.

GENESIS.
God had “His way” (Gen 6:12) way before Moses (and Leviticus laws) of which clean and unclean beasts was part (Gen 7:11 , Lev 11); Gen 9:4 and Lev 17:10; en 19:7 and Lev 8:22. Altars, thanks giving and other offerings, feasts were done onto the Lord before Moses i.e by Noah, Abraham Gen 13:18; 31:54; Gen 15:10 not dividing bird and Lev 1:17., Gen 38:8 and Ruth 4:1-8 (surviving son marries dead brothers wife) also in Lev laws.
Covenant with Abraham as a family and Moses / Israel as a nation was on condition they “walk before me and be perfect” Gen 17:1-2; 18:19. In Gen 26:5 Abraham kept the same commandments (Hebrew word H4687, mitzvah), as was given to Moses in Ex 24:12. There are other Hebrew words meaning commandments that could have been used rather than the same specific one!

In Gen 22:7 little Isaac knew of offering / sacrifice custom. He used the word sacrifice and specified the type of animal rather than say animal, cow, ass or other no acceptable beast. Obviously the offering system was known to his father who taught it to him. Abraham also exercised faith in God and it counted to him for righteousness not only in the scripture quoted by Paul in the N.Testament; but Gen 24:7 “he shall send his angel…” Isaac went out to pray at the “eventide” which could be afternoon pray time as kept by the apostles and Daniel 6:10, Plasm 55:17, God told Israel not to marry into other nations as they would be a snare as happened with Solomon. Yet this was known by Isaac (Gen 26:35) as why he commanded his servant not to bring his son back to the pagan land to find a wife Gen:24:8. also 28:8. Ofcourse no graven images as in 31:19 and Ex 20:
Gen 23:10 At the gate in front of witnesses is what the law given to Moses later said and this can be seen in for example Boaz agreeing with Ruth’s nearest kin to take Ruth as his wife (Ruth 4:1).

People keep thinking that the law started with Moses which included the feast (holy) days of Leviticus 23. The law is to do with partly remission / forgiveness of sins; but also other things as the feast days of God. Sin is transgression of the law. So if there is no law means no sin. In Noah’s time they sinned continually and obviously they were breaking God’s law way before Moses otherwise there would be no need for God to get angry with them if they were not sinning, breaking the law. The O. Testament talks about “His way”. They had corrupted His way, keep the way of the Lord etc confirming God had a way which included keeping the feast of 1st Fruits as done by Cain and Able in Gen 4:4. Was it not that feast there would be no need to use the phrase. It also shows this was not a sin Sacrifice; but a free will offering at an appointed time.