Some believe Moses wrote Genesis. Some believe he wrote it when he was with God for 40 days and nights on Mt. Sinai.
God was there in the beginning and He remembers what He did on those 6 days. Could He have told Moses what to write or perhaps written it down Himself? I don’t see why not.
Language was most likely ancient Hebrew as that was the language of God’s chosen people and they kept the Book of the Law.
God’s intent, I believe, in writing Genesis was for us to read it, believe what He wrote, understand His love for us and His awesome power, repent of our sins and quit trying to run our own lives. Allow Him to direct our hearts and in so doing, demonstrate His love to others.
I believe this because to me that is the message of the entirety of the Bible and it is also the reason for the peace that I have in my own heart.
These are reasons to not try to attempt to prove matters of faith with science or assign special credibility to scientists who happen to agree with you.