Don

My understanding of the 1st sin was the man just standing there and not saying anything when the serpent tempted the woman, as he knew better and was charged with guarding the garden.  This is why God tells him a reason the ground is cursed is “You listened to the voice of your wife…”

On the “not good” I understand that in the sense of “non-functional”.  The human alone could not function in all ways God intended.  Gen 2 is about 2 lacks, the lack of a human to irrigate the land, which God addresses with the human, and the lack of the human to be fully functional like the rest of creation, which God addresses by splitting the Adam/human into male and female.