If you know nothing about hacking i suggest you don't get your hopes up. It takes a TON of learning before you will be remotely close to making an esp. First of all - what language did you want to write it in?
If you want to write it in C++ then you need to learn the basics of hacking in C++. Here's a little video to help you out, but no one is just going to say "Hey this is how you do it." Because it is not that simple. Good luck my friend.