A good way to learn cracking is from search engine for game training. game training allows you to play god in video games.
Unlimited lives, invincibility, maximum gold and weapons, etc. For those just starting out get a game trainer software and start using it with help files on or off the internet. you do not need to know how they function as it is quite obvious when you use one. not to say you can not train a bank or cash institute for maximum funds given what you learning in game training. Most game trainers work on debug registers and interrupt routine. like press a button to freeze all running software and jump into the game trainer program. I will post links here for you to study.
using game trainer to train a game
using cheat engine
How to make a trainer with Cheat Engine
how to write patch files
that's all for now.