Exodus 1 - 4
Between the last verse in Genesis and the first verse in Exodus some 400 years have gone by, and everything has changed in Egypt. Israel’s descendants out number the Egyptians, and they are now being persecuted as slaves. God raises up Moses as His appointed man to lead Israel out of bondage in Egypt.
As a child Moses is raised as an adopted grandchild of Pharaoh, but later flees Egypt and lives in the Midian desert (now Jordan) for most of his life.
When Moses is 80 years old God appears to him in the desert, and calls him to be His ambassador to Pharaoh, and to lead Israel out of slavery. God declares Himself to Moses as “I AM”, which is the Hebrew verb form of His own Name (Jahweh).
So Moses goes back to Egypt, meets with his brother Aaron, and then the leaders of the tribes of Israel, proving that God sent him to lead them out of that land.