One outlet causes all power to go out
It sounds as if you have a bad connection in that outlet as it feeds other fixtures and outlets downstream. The pressure from the cord is probably pulling the connection closed, and it breaks when the pressure is removed.

This may be due to a loose screw, a broken wire, or a defective outlet body. 

It also sounds as if you have little to no experience in dealing with electrical circuits. They can be dangerous for the inexperienced, and you may wish to bring in a professional (or an experienced friend) to help solve the problem.