[neverg]

What has been said and get to look at someone else's code. Pick a simple addon and see how things are done.

This should help you out:

https://us.battle.net/forums/en/wow/topic/20742244205

http://wowwiki.wikia.com/wiki/AddOn_...l/Introduction

http://wowprogramming.com/

https://wow.gamepedia.com/World_of_Warcraft_API

Then take a look at some addons, you can explore what Roth in his addons for instance: https://github.com/zorker/rothui/tree/master/wow7.0