The main breaker panel has the grounds and neutral hooked together and has bonding screw installed. Where do I put the ground wire for the sub panel? Do I put it on the neutral bare where the white neutral is also? So the main panel would have the ground and neutral wire for sub panel on the same bar? Also should I leave bounding screw off on sub panel?
In the main panel, put the neutral where all the other neutrals are. Put the ground where all the other grounds are. Good chance they are all going to the same bus, that is fine in a main panel.
In the sub-panel, yes, ground and neutral must be separated.