how do i use the cheats in game i got 3.03 oe-c do i need any programs please post

im kinda getting sick of people who dont search (not just you)

get that and theres plenty of tuts here to help you get it installed
http://www.cheatdevice.com/gta/VCSCheatDevice23a.zip

well ok that did work but how do i bring up the menu in game hwat buttons do i press

L + Up on the D-Pad.

it should pop up when the games loading (at least mine does)

Yes it does and should make sure you have it activated(on) by turning off your psp turn back on and while it's starting up hold R trigger then go to Plugins then make sure it's on right in there.