It seems daunting, but shouldn’t be. We’re generally a friendly lot. Front door is always open during opening hours so just walk in to the tiny lobby. Staff will then buzz you in. Membership is free and gives reduced entry – they’ll ask for your name and date of birth; if you look young they’ll ask for proof you’re 18. They’ll give you a towel and locker key, and receipt – keep it, as it’s a voucher for reduced entry within 7 days. If you want they’ll give you a tour, or you could just explore any unlocked area. Etiquette is basically: don’t be shy, decline politely if not interested, tell the staff if there is a problem and let them sort it out.
If you’re obviously drunk they may refuse entry. Condoms and lube are available throughout the rooms. You are don’t have to do anything if you don’t want to.