Hello, The replacement fuel door hinge is available in many places. The rivets are merely straight pieces of round stock. You push them into the body with a punch or smaller diameter nail to remove them. I dropped one of my replacement rivets and simply used a nail with the head cut off. Use a caliper to measure the size or simply test fit.
As far as assessing the damage to your car goes. Clean the mud off it, if any, drive it up a set of ramps and look for leaks and dents. Take it for a ride on a quiet street where you can drive at various speeds. You'll feel any damage you caused to the wheels or steering gear. The steering wheel quickly goes off center whenever you bang something. Kira