Genesis is the book of "beginnings" or "generations". It has two distinct parts.
The first part, chapters 1-11, deal with the Creation, the Fall, the Flood, and The Tower of Babel.
The the second part is about the four generations and patriarchs: Abraham, Isaac, Jacob and Joseph, and covers the rest of the book from chapters 12-50.
Genesis is the foundational book to the whole Bible, but more than that, it is the foundational book for life. Without it, there is no basis for the Cross of Christ. When it is understood, it gives man the only true framework by which he can know how and why things came to be the way that they are. We can also see how God immediately began His plan to redeem mankind and the earth from it's tragic state. It speaks of the power, creativity, love, and redemption of God. That's just the beginning. So, begin your study of Genesis, which is the oldest of all books, and contains the first words ever recorded in all of history - "In the beginning God created the heavens and the earth." Gen.1:1