First of all we are talking about a hole that is no larger than the size of a baseball.
The first thing you want to do is find some newspaper to stuff in the hole. Before you do that, open each sheet of newspaper and crumple it up. Then stuff like three pieces at the same time to hold it in place.
This way the newspaper doesn't fall into the wall all the way to the floor. If it does fall into the wall, don't worry just crumple up twice as much the next time you stuff it into the hole.
Now you need to get some spackle or wall board joint compound from the hardware store. You need to get it pre mixed to make it easy. Then be sure to get a three inch and a five inch putty knife to apply the compound to the hole.
You are now ready to patch. Open more newspaper and flatten it on the ground in front of where you will be patching to catch any mud that you drop. Next open the lid to the small container of joint compound and get enough on the smaller putty knife to smear it on the wall where the newspaper is.
Be careful not to push it in too far. Remember, the idea is to apply the drywall mud to the area to patch. So don't apply too much pressure but enough to get it to stick. Start at the bottom of the hole and straight across work your way up.
Patience will guide you to complete this project. Put a light first coat on and let it dry, then tomorrow at the same time you can put the top coat on to smooth it out to perfection.
When you are all done, you can sand, primer and paint it to complete the job. This is the fastest way to patch a small hole. Remember to put a stopper on the door if that is what caused the hole. Be sure to prevent the cause from happening again.
Congratulations! You have now patched a wall on your own!