How can I add new weapons to an existing mod?

Basically the title, I wanna make a modpack with Ice and Fire but there doesn't seem to be any weapon mods that are compatible with it - I want to get into coding and gamedev anyway so I might as well do it myself. The idea is to take Mortius' Weaponry and add dragonbone/dragonsteel variants to the weapons in the mod, which should be simple enough since I'd have to pretty much just recolor the models and copy paste some unique ice and fire passvies on the weapons but I literally have no idea where do I even start and have rather basic coding knowledge, so some kind of help would be appreciated!