ok, this may sound like a pretty amateur question, but how do you get/control feedback from you guitar/amp????

just a general query, wondering if someon could help me out

Lots of volume or gain/distortion can get you feedback. You can kinda control it with the volume knob on your guitar.
My Gear:
American Deluxe HSS Strat
Crate GT212
Vintage '66 Fender Champ Amp
Dunlop Crybaby 535Q
Jekyll & Hyde Ultimate Overdrive
Vintage '74 MXR Script Phase 90
Vintage '77 MXR Flanger
Orange Squeezer (clone)