test mod help

[scary.]

Hey, I'm trying my hand at modding with my friend for this game, we're both 3d artists and just intend to add creatures and armor to the game so far, are we required to get our hands in some C#?
My second question is currently im just trying to implement a simple mask into the game do I need to make a content pack or a code pack? and how would I go about creating this test mod in the first place? As you can tell im extremely new to this game and to modding it however im struggling with the information provided in the current modding tutorials for they are too vague for me. Thanks in advance.

[Soloquendi]

There is a walk through on basic modding for the game in the wiki.  It's very helpful.