Spaceship floor-plan design software, or something like that
I would love for the program to be able to display multiple layers (so I can get many decks of said spaceships on top of each other, so they are similar enough in size)
I don't really have much experience in actual drawing so the simpler the better.
Edit: Found a website/program thats free and produces sick looking futuristic maps. Here you go: https://deepnight.net/tools/rpg-map/
Worst case scenario I can cut out the rooms and creata an unholy amalgamation of FTL rooms.
For myself I'm using the cosmographer add-on for campaign cartographer. That is a professional mapping software (see https://www.profantasy.com/products/cos3_examples.asp) and as such anything but cheap, but if you're looking for a real mapping tool that is in the top classes with all its tools (for example the city add-on let's you draw complete streets with random houses attached as simple as drawing lines).
A much cheaper alternative are the many starship construction games available on steam. By that I don't mean FTL (which basically has prefabricated ships) but programs like "starship cooperation" where you design floorplans of the ships and assign routes to crew to keep it running with connected systems.
And to get them cheap, check www.isthereanydeal.com for the best reseller, most of them are on sale several times a year. (starship cooperation for example is officially 20$ but it had been available for 4$ and less in the past)