What are the changing rooms/ bathrooms ect. like at sex clubs? Are they separated by gender?
Is it common to have an area where people wear more clothes and an area where full on nudity is allowed? Do those areas have different changing rooms? Or are the changing rooms more private like cubicles? What's the capacity (maximum guests) like at an average club? How many guests might be showering/ changing in the same room? Are there any websites that might have more information on this?

I want to write a fanfic and while I can write anything, I hope my imagination isn't too weird and naive and I'd love to learn more about these types of clubs in general :)
Thank you in advance and apologies if these questions are silly.