Hi and thanks for using our service! My name is XXXXX XXXXX I will do whatever I possibly can to give you the most accurate answer.If there is a sloped apron at the door, that prevents water from coming under the door, I would remove the door and just build a wood framed wall in the opening. Use pressure treated sill plate and flash the outside plywood sheathing with metal flashing at the bottom. The metal flashing should cover at least 6 inches of the bottom of the plywood and slip into a gap between the garage floor slab and the apron. If there is no existing gap, I would sawcut one in; this will keep the water out.Painting the block walls and the floor should seal any smells. If you install furring on the block walls and the drywall, that will help seal the smells as well. Also, installing a floor such as carpet will help seal smells as well.