I don’t know what is your skill level, so it is hard to help. I actually don’t know how to do it myself either. But make sure you at least understand these: Startermod_basic updated with weapons, armor, lights, and particles
Then you can take a look at [Mod] (A20) The Bastioneers! More Dangerous (and Mod-Friendly) Than Ever! Help me test for A20!. The guy added an entirely new race. So is a good place to look if you are trying to add a new race too.