Controllers?

Would I be able to purchase a controller that looks similar to a ps2 controller with similar buttons (2 joysticks, 4 main buttons, a few at the top, a start and select, etc.) or perhaps get some kind of adapter that would allow me to plug a ps2 controller into a pc and then play that game using the controller just as though i was using a playstation 2? sorry if this sounds stupid, but i'm very new to this whole thing.

There are PS2 adapters for the PC but you could also try to get a USB controller that looks like one.

I have such a controller and it works fine.