Something like GM would have to be done with send and receive packet's. I'm sure there's different way's ,but that's the method I use for those type's of cheats done using
wpe ,but that's just A personal preference to my liking. Learning fast is great ,but you don't want to jump into the big dreams just yet until you have some firm small scale experience in what you're doing. You don't want to have more questions then answers for your own task although there is never nothing wrong with asking no matter how stupid something may sound to other's never let it fade you because you have A stronger will to learn more likely so then them.
A great place to start learning about packet's is here:
http://wpepro.net/
Ask questions in the forums and read tutorials or other asked question's. If you want to get more into memory hacking (which also has very good results) then stick around here and ask question's (we wont bite =]) ,but keep A strong search ethic for tutorial's across the net.
To get started: Use the F1 command inside
MHS should you choose not to learn packet handling.