There are some stuff that you can use cheat engine with, but's it's hard for me to explain... and i don't plan on writing a tut on using ce...
oh yea i forgot to say what you can do with it, but if you learn how to use ce good, and know the values of most of the stuff in the game you can do almost anything... use ak47's, inf ammo, inf nades/mines , trust me... theres alot you can do but im not gonna lie... it gets kinda tricky, if you don't want to get confused, then learn ASM, and learn a lil bit about hex values.