Since this forum is about competition, and not shooting from a bench, you need to start with the fundamentals: stance, grip, sight picture and trigger control. I suggest you get going with shooting lessons from a Grand Master USPSA shooter and buy Brian Enos's book.
While this is true, group shooting is something that Brian used often. If you can't shoot nice groups from a rested position, you will never be able to shoot a nice group free style.