itch.io

I literally cannot figure out where to go to find out where to begin. I would like to make a couple of mods, but maybe start with something small-ish like making all of the IDPD weapons available to be used by the player. I don't know if that's even feasible because I don't know anything about this stuff, but I want to start. Can anyone give me some resources and lend a hand on how to approach a task like this, or maybe just what kind of mods to start with. Thanks