Anyone able to help me get started on making re-texture mods?

I have a lot of mods that I would love to use if they weren't as odd-looking as they are, and I was wondering how I would get into making retexture packs for mods, then publishing them onto the workshop (with sources of course).

I have little experience in modding other than looking at file directories and using RimSort, and zero knowledge of publishing mods to the workshop, if anyone can direct me to some help that would be awesome!