Help on how to get started

So I really want to draw but I don’t know where to start? I have drawn before but I really want to improve. The things I draw are usually things I saw and decided to draw it, but I would like to make up my own characters. But I don’t know where to start. Should I learn how to draw the human body or hair or eyes or face? Or should I learn how to shade or something? What supplies do I need exactly or does a piece of paper and a pencil do just fine? WHERE DO I START???!?!