Like in the ZZ mech mod you can teleport to a ship that has an npc and some objects on it. How would I somewhat replicate that, is there a tutorial or something?
Strictly speaking, the ship probably isn't a ship at all. Not that I've checked the assets of zz mech mod. But I'm fairly sure it is a dungeon so not really different than warping to any other "mission". Do you want to make an actual custom ship - for actual use as a ship - or a dungeon that seems as though you're on a ship? The method isn't the same, and I haven't played with dungeons yet. But the old way dungeons where made is similar to how ships are now. If you want to make custom ships... now that I can help you with. Assuming of course you have specific questions. As for replicating what happens in ZZ mech, the thing I'd most recommend is to download it and examine what they did. If I'm right about it being a dungeon, you may need to use Tiled, and search around here for tutorials on using Tiled. You might also consider asking that mod's author in the discussion tab of that mod. After all, no one knows what they did better than the person who did it. But look at their assets first so you can ask specific questions about how things work and various aspects you don't understand.