What would have happened if Adam and Eve wouldn't have eaten from the tree of the knowledge of good and evil? Would we still be in the garden?
It is impossible to speculate on where we would be if Adam and Eve had not disobeyed God, but it can be fun.
I would assume that God would have allowed us to advance just as humanity did. The trajectory would have been different, in all likelihood, since war and disease have been chief drivers of technology over the years and those wouldn't have been issues. But God would have been with us and perhaps we would have been even more advanced with His help than we are now.
There would be no curse on the ground, no death - and thus no impetus to have large families to survive so the total population might have been less. Food would be plentiful and everyone's health would be fine. There would be no jealousy or other evil desires and emotions motivating mankind. If you can imagine heaven on earth, that's what I think it would have been like.
Of course, Satan would have kept trying to stir up trouble, and there is no way to speculate what effect his continued meddling would have been. But being on good terms with God would be a very good thing in trying to eliminate his problems.
Having God come down and walk with you in the cool of the afternoon must have been great. If Adam and Eve had done that, they might have avoided the fall. God's there today to help us to keep from falling as well. If you don't have a relationship with Him, you should.