Abram was born 1948 years after creation. He is the 19th descendant from Adam. Noah the 9th descendant of Adam was still alive when Abram was born, and lived an additional 58 years. Shem, Noah's son was 290 years old and outlived Abraham by 35 years. I personally believe that the first book, Genesis, was written before Moses came along and that Abram was involved in it in some way. He likely spent many times listening to stories of creation and the "family history," of the time when God dwelt with man and the world was pure. Stories of the flood and the decadence that caused it, which likely came from an eye witness, in fact i would think it highly unlikely for him to not have heard these stories. Noah had 84 years to get the story of creation from Adam's grandson and given the "warts and all" integrity of the whole Bible, could be one reason this particular branch of Eve's seed was chosen. The Bible says Abram was 75 years old when he left Haran, where he moved with his family from Ur. It does not say how old he was when they left Ur where the survivors of the flood were but it does say that he was already married. Another factor is the change in writing style and information given after the Egyptian enslavement of Israel. Until the death of Jacob we are told of the patriarch's age when the child that would continue the line was born, how long they lived, ect. and before Abram very little else. From the end of chapter 11 the narrative gets much more specific and seems to be written by someone close to Abram, if not him, perhaps Jacob or one of his sons.
During 430 years of Israel being in Egypt, we are told almost nothing until the story of Moses Begins in Exodus chapter 2. The first chapter containing some 300+ years and 1/3 of that being the story of Pharaoh's order to kill the male children of Israel because they were more numerous than the Egyptians. If this order were carried out for more than one generation there wouldn't be many Hebrews left. It seems the devil always tries to kill the children when God is getting ready to do something.
Finally there is a reference in Exodus 16;33,34 where Aaron is to take a pot of manna and "lay it up before the LORD, to be kept FOR YOUR GENERATIONS. As the Lord commanded Moses, so Aaron laid it up before the TESTIMONY to be kept." The first time Moses is commanded to write something down is in the next chapter 17;14 after the battle with Amalak. The children of Israel didn't get to Sinai until chapter 19.
We are told that Terah had three sons, Abram, Nahor, and Haran, and that Haran had a son named Lot and died. We're are also told Abram and Nahor both took wives and that Sarai was barren, all while they still lived in Ur "the land of his nativity." Terah takes Abram, Sarai, and Lot and moves from Ur "to go into the land of cannan; and they came unto Haran and dwelt there." We don't know if Haran was already a city or if they founded it, it is the same name as Terah's son that died. It is not clear when the Lord began speaking to Abram, (if he was as hard headed as me it may have been some time) but it does say he was 75 years old when he left his father in Haran. Terah lived an additional 60 years and died in Haran, he was 205 years old.
In Genesis 12;1 the Lord tells Abram to;
1. Get the out of thy country,
2. and from thy kindred,
3. and from thy fathers house,
4. unto a land that i will show thee.
The Lord then gives him the promise, "I will make of thee a great nation, and I will bless thee, and make thy name great, and thou shalt be a blessing. And I will bless them that bless thee, and curse him that curseth thee: and in thee shall all families of the earth be blessed." Abram obeys three fourths of the Lord's command but takes Lot with him. The journey takes one year for Abram, Sarai, Lot, "all the souls they had gotten" and their substance. I suppose when one lives with their parents 75 years and one or two hundred altogether they could collect a lot of stuff. After they arrive in Cannan they passed through the land and came to Sichem in the plain of Moreh. The Lord appeared to him there and said "unto thy seed will I give this land" and Abram builds his first altar in Cannan.
Abram moves from there to a mountain East of Bethel and builds his second altar and calls upon the name of the Lord. If the Lord answered him there, the Bible says nothing about it. Abram continues to travel toward the South.
When a famine came and was bad, Abram went into Egypt to escape it, Gen. 12;10. As they approach Egypt he makes an agreement with Sarai to pretend they are brother and sister because he was afraid they would kill him and take her. Apparently he had not learned that God was his protection yet, one of many lessons he would learn during his sorjurn in these alien lands.
After they get to Egypt and the inhabitants see that Sarai is good looking, the princes recommend her to Pharaoh, who brings her into his house. Gen. 12;16 says this "and he entreated Abram well for her sake: and he had sheep, and oxen, and he asses, and menservants, and maidservants, and she asses, and camels." I'm not sure if this is a description of Abram's possessions, or a gift from Pharaoh. The Lord plagued the house of Pharaoh with great plagues for Sarai sake and Pharaoh calls Abram to task for his dishonesty. He then commands his men to send him away with his wife and all that he had.
Abram returns from Egypt very rich in cattle, and silver, and gold to the place where he was before, Bethel, where he had built an altar and again called upon the name of the Lord. Again the Bible is silent as to if the Lord answered, though i tend to believe that He did not at least not in a significant way. Lot, who was still with him, also had cattle and servants and the land was not able to support both of them. They begin arguing and Abram tells Lot to choose which way he wanted to go so that they might separate, and he would choose the opposite. Perhaps the Lord answered Abram by allowing the strife between his men and Lot's, who was not supposed to be with him. Whether that is the case or not, they separate, Lot "walking by sight" choosing the well watered plain of Jordan which before the overthrow of Sodom was as the "garden of the Lord," 13;10. "But the men of Sodom were wicked and sinners before the Lord exceedingly" vs. 13. Thus Abram finally becomes fully obedient to the Lords original instructions and is immediately rewarded in vs. 14. And the Lord said unto Abram, after that Lot was separated from him. "Lift up now thine eyes and look from the place where thou art northward, and southward, and eastward, and westward: for all the land which thou seest, to thee will I give it, and to thy seed forever. And I will make thy seed as the dust of the earth: so that if a man can number the dust of the earth, then shall thy seed also be numbered. Arise, walk through the land in the length of it and in the breadth of it: for I will give it unto thee." So when the Lord got Abram in obedience to the place and condition His plan demanded He, the Lord, confirms the promise, adds greater understanding to the limits and extent of the promise, and gives Abram new instructions. Gen. 13;18 "Then Abram removed his tent, and came and dwelt in the plain of Mamre, which is in Hebron, and built there an altar unto the Lord." This is Abram's third altar that he built and it is curious that at this alter he does not call upon the name of the Lord. Personally i think he is learning to walk by faith and beginning to use his altars for worship and thanksgiving instead of asking why and when. This is a lesson much easier to talk about than to learn, but you will never find the will of God until you learn to do what He says and leave the results to Him. Thank God He is willing to sometimes maneuver us into a position of obedience.