The word literal can be very confusing. Like the word metaphorical, it is a word that refers to the way that words refer to things. Whereas what we often mean is the distinction between concrete and the abstract.
Concrete- being something definite, substantial, physical.
Abstract- being like an idea.
You can refer to something metaphorically, to something concrete–Like if I call my car the old tin can, thats a metaphorical reference to something that is definitely solid.
Or, you can refer literally to something abstract. If I say Plato’s theory of forms, that theory is itself an abstraction and the forms are themselves abstractions. (doubly abstract) but I’m referring to it.
When one says, is Genesis to be taken literally? That doesn’t settle ahead of time exactly what it refers to. And when we are reading any text, it ought to be an open question- What does this text intend to refer to?
Example: LK 15 Jesus says, there was a man who had 2 sons … It makes no sense for me to say — I need to know the name of the farm and the name of the father, so I can visit him… Jesus and his hearers would have said to you, don’t be silly — It’s a parable.
You have to go case by case.
The story could be fictitious, but the meaning remains concrete. It’s a much more interesting and complicated question than your culture and mine has ever allowed us to get into by this literal, non-literal split.
So taking all this to Genesis, we might ask, what did they intend to do by this story?