How do you do people moves in Street Fighter 4 for PC and where a place where in they tech you to do moves?

I have Street Fighter 4 the video game for the pc and I only know how to play good with Ryu an Ken.(I believe they both have easy ways in doing they moves) I also know how to do all Ryu and Ken moves and Ultra attack but with others characters like Guile, Vega,Sagot, Chun-Li and the rest are hard. I don't know how to do other people moves in Street Fighter 4 in pc except Ryu and Ken. Some have confusion moves for the keyboard that I do not know and it had to know how to do serton people moves. Can someone tell me where a place in the enternet where they tech you how to do people moves or help me to do people moves in Street Fighter 4 for pc because I am having a hardtime playing with people and beating storying mode.