We moved into this house and I'm trying to redo my daughter's bedroom. This is the problem.

Top half of room was painted in a semi-gloss eggshell paint
Bottom half wallpapered. Nothing on drywall...maybe some sizing.
Ceiling- When we removed ceiling fan we noticed not even connected to anything and drywall all busted up. Husband cut out drywall and conneceted ceiling fan to joist. Now large patch of new drywall in center of room.

Question: I started by reading tips here. I sanded all the walls and washed them down. Now after hubby stepped in we have so many surfaces to deal with. Should we go and get a gallon or two of primer and prime the room first and move from there?

Thanks for help.