Why the whole Adam and Eve Fall story makes no sense

[Mudhammam]

Rather, it represented free will.

How does one choose free will?

There is a point in the human experience when the mind acquires a conscious awareness that the choices one makes carries or entails moral responsibility. That awareness has been equated with a freedom to will different acts that are conceived by the intellect to accord with or diverge from right reason. The prohibition to eat the fruit - symbolic for sensible pleasure - is allegorical with the moral conscience, and the choice to do or not to do so represents the free act of the will. The "knowledge of good and evil" is the responsibility, and in this case guilt, that one associates with right or wrong behavior. That's the point of the story. It's like the OP is asking, "Why did Cronus eat his children if he's a god and when there were livestock on the earth?"