i cant seem to find out how to even use mods my dude

i doubt the more than 1 shipyard supported is doable, as for the first part, i would think a list that had a few ships might be able to be written in as a build option or maybe an exploration mission that rewarded several ships as a workaround. either of those would have to be coded outside the game, and wouldn't be modifable once you started a game.

as for using mods, if you have crusade the folder is typically in a "your r name"/mydocuments/games/gc3 or gc3 crusade folder, and can be downloaded from nexus mods. workshop items i haven't bothered to toy with yet.