it's not imcomplete, it tells you everything. Look outside of Genesis alone.

jerimiah 4 tells you about the creation and the earth age before it that God destroyed.

3 earth ages, we are in the 2nd. The earth is millions of years old.

22 For my people is foolish, they have not known me; they are sottish children, and they have none understanding: they are wise to do evil, but to do good they have no knowledge.

23 I beheld the earth, and, lo, it was without form, and void; and the heavens, and they had no light.

24 I beheld the mountains, and, lo, they trembled, and all the hills moved lightly.

25 I beheld, and, lo, there was no man, and all the birds of the heavens were fled.

26 I beheld, and, lo, the fruitful place was a wilderness, and all the cities thereof were broken down at the presence of the Lord, and by his fierce anger.

27 For thus hath the Lord said, The whole land shall be desolate; yet will I not make a full end.

28 For this shall the earth mourn, and the heavens above be black; because I have spoken it, I hav