It may sound funny, but you may end up with holes in your drywall by simply hammering a nail with too much sense of responsibility and determination. Drywall is made of gypsum and paper, so it does make sense for this to happen. A while ago, repairing this would have asked for removing a section of wallboard between two studs. Now there are solutions that make the problem simpler to fix, like using mesh patches to cover small diameter holes. A patch has a sticky back that will adhere to the surrounding surface and its size can be up to 8 square inches.
These are the items you will use to fix the hole: an utility knife, sanding block, a mesh wall patch that is about 2 times the area of the hole, joint compound, tray that will hold it, a 4″ or wider putty knife and a sponge.
Since a lot of dust may be raised, cover the floor and the surrounding area with newspaper before you start the job. The surface where the patch will be placed needs special preparation: cut any hanging bits with the utility knife and sand the edges with sandpaper or sanding block. Be careful not to make the hole bigger during this procedure. The mesh patch is covered with backing paper that you will peel off before centering the patch over the hole. After centering it, smooth the edges. Put the joint compound in the tray and then apply it over the patch and beyond its borders, using the putty knife. You will use the tray instead of getting the compound right out of its container so that you don’t allow the entire quantity to dry while keeping the lid off during work. You will then smooth the compound with moves from top to bottom and from one corner to another. It will take about 8 hours for the compound to dry. Sand the dried surface with sandpaper, 80-100 grit. Sponge the area to wipe the dust off. A second coat of compound will be applied and smoothed. After it is dry, sand the area with a fine sandpaper, 120-150 grit. Clean up and then prime and paint to finish the job and obtain a nice looking wall.