Hey Guys! What's Up? T3XASF1RE Here!

Today, I want to start some modding, but I am relatively new to the modding itself. If anyone can help me with this, I would greatly appreciate it. All I want is a simple tutorial to allow me to learn to make mods.
And, no, I do NOT want a program to make mods for me....I want to actually be able to make them myself, but as I have no prior knowledge of how to do this, I'd like some help.

Thanks!
-T3XASF1RE