Basic Hack

Hello
I want to start code my own hacks but i have no idea how to do it
Ok, this is stupid:
Addys (adresses?) means some value in game (like reload?)
For example Change Addy X123 - 0 (no reload? :P)
OK now i want some basic ideas, what program i use to create dll and basic code lines and if possible values
Tanks in advance
Dont judge me cause i never coded a hack, sorry im noob
This is questions
Hope an answer