1. Hold a bright light beside the drywall screw heads and drywall joints and either add mud or sand it down to get the surface flat with the surrounding wall. Repeat Step #1 until the joint compound over the drywall screws and over the joints is smooth and flush with the surrounding wall surface.
2. Prime with a latex primer.
3. Paint with a latex or oil based paint.
You should decide what you want to do with the bare concrete. During the spring, there will be condensation forming on that concrete because it will remain cold for a long time come spring. You probably want to anchor spruce 2X2 strapping to the concrete and insulate that concrete and cover with either drywall or a more water resistant material like Georgia Pacific "Dens-Shield".
If it were me, I would use extruded polystyrene foam as the insulation rather than fiberglass. Extruded polystyrene foam is impermeable to air, and so it doesn't need a vapour barrier. You simply press it into the space between your 2X2's, fill any gaps between the foam and lumber with expanding polyurethane foam, cut off any foam that sticks out proud of the lumber, and cover with drywall or Dens-Shield.
I'd be inclined to use Dens-Shield over concrete simply because the cold concrete behind the Dens-Shield and polystyrene foam is going to suck up heat like a sponge come springtime when the weather warms up, and I'd be concerned that condensation would form on any drywall in the vicinity of that concrete.