How do you get rid of scars?

I just want to know. When I was younger sometimes i would scratch them so I think that might be the problem. i NEED them to be gone really soon but I know this isnt something that will happen over night though! Please give me what I need and tell me how long it will take to work. And if you bought like a cream or something that really works tell me what it is because I dont mind just going to CVS or walgreens or whatever. Oh and remember please tell me how long it takes to work