Is there even proof in the Bible that God created the world and manking?
Let's consider that 100% of the bible was written in good faith and none of the prophets and other human characters were hallucinating or lying, so every first-hand account is 100% true. Logically, Moses wrote Genesis but he didn't received the knowloedge of the world and makind creation from another person, so it can't be confirmed, same for anything that happened before Moses.
As far as i remember there is no person in the bible that attains any confirmation that God created the world or mankind, so there is a possibility that God and his agents are lying to people all along.

Strict proof? No, but there are all sorts of motives of credibility. I'll skip all of the fluff and jump right to Christ. He fulfilled the prophecies written centuries and centuries before, and even came in the time of the Romans like the Book of Daniel predicted, and as the Psalms and the Prophets say, when the Christ comes, all of the nations of the earth will come to worship the Lord. And so it happened, and many miracles have taken place since the foundation of the Church of Christ and the gates of hell have not prevailed against it. Christ was vindicated by God in His resurrection, which was so convincing that the Apostles and enemies of Christ such as Paul were persuaded to leave behind their old lives and to die for His sake.

On top of this, the Bible tells us the will of God regarding our behavior, and what sort of lives we will live if we follow the way of the Lord, and what will happen if we do not follow His ways. Through experience, I have come to know that the way of the Lord is perfect, and that sin is harmful and only leads to suffering. Yet another motive of credibility for the Scriptures.

Why should I doubt God? He has never wronged me.