Overall, the most important thing is that you place your trust and faith in Jesus as your Savior.
Having done that, you read His Word. It says:
John 1:1 In the beginning was the Word, and the Word was with God, and the Word was God.
2The same was in the beginning with God.
The Word, is also the Bible.
Genesis is true, as written. God and Jesus being one, and the Word, I’ll beleive Them/Him rather than a mans theory.
You are confounding the Koran with the Bible. The Koran is supposedly kept in Heaven and the Earthly copies faithfully reproduce it. The Bible, though, is written by human beings inspired by God.