Read Genesis from 1:1 to where Noah appears in 5:26 and you will notice .... almost no information of how the original Jews based their religious life and what codes they lived by.
We can discern from the eden story that we should obey God, and shouldn't lie. And from the Cain and Able story that murder is wrong and that God seems to approve of the idea of sacrifice..
and that's about it.
...The Seven Noahide Commandments comprise the most ancient of all religious doctrines, for they were given to Adam, the First Man, on the day of his creation.
Wondrously, the Seven Noahide Commandments remain the newest and most uncharted of all religious doctrines. Humanity has managed to keep them new by ignoring them throughout history.
But now, in these latter days when the footsteps of the Messiah can be heard by all who will listen closely, the Seven Noahide Commandments must finally be studied and observed by all the people of all the nations...