PSP HACK PROBLEM HELP PLEASE HELP!!!!!!!!!!!!!!!!?

guys look i bought a psp about a month go. i tried to hack it but i couldn't.A friend of mine advised that i needed to update it for more good graphics. So i did he brought the CFW for psp 3004 vr 6.38 (which was my psp's version) but it did not work so i waited for the correct one.Days later i downloaded a demo from my pc and tried to transfer it to my psp but i failed but i downloaded it through my psp and checked my mem stick through games and there it was.So i tried full games but it was a bad luck for me.help me please i want atleast one full game right answers will get 5 star ratings and votes