Best way to understand is from original language and meanings. This is one of the best videos I have found explaining the garden of pleasure myth

It is based on incest and is all a part of god's plan. God was once so upset with sinful mankind that he decided to destroy them all and drown everyone except for 8 people. In his great wisdom this left it all open to once again populating the earth by incest. Just leave it to god.

There are TWO creation myths in Genesis
Chapter one has humans created, male and female, be fruitful and multiply
Chapter two is the Garden tale, where God made his CHOSEN people (Adam and Eve)

Wives came from the land of Nod (where the humans from chapter one dwelt)

Not saying it makes sense, just touching on the general idea, which varies a little sect to sect, and this same thing is used by white supremacists to justify racism via Christianity.

Stupidity knows no bounds. No matter how low my expectations are, these people exceed it.

Or who everybody (!) )procreated with....

It is my opinion that the biblical creation story is simply the mythical story of how the Hebrew people came to be and has nothing to do with the rest of the planet. All tribes and cultures have their own creation stories and this is no exception.

Incest was common and accepted in the beginning.