Puppy help?

I got a pupper in the beginning of September and I’m having a small issue with him. It’s nothing really big besides biting (hes 5 months old) and potty

Well my dog for some reason is unlike a normal dog apparently and REFUSES to go potty on the grass and will only go on the rocks near my window. If you have any advice on how to fix that, so that when we take him out of state he goes potty, please let me know 😅

Also, how to stop puppy from trying to nip at face?