What to expect at a bathhouse

Hi. I'm a pretty inexperienced guy hoping to change that soon. I've thought about paying a visit to my friendly neighborhood bathhouse but am just a bit nervous about what to expect. I've poured over the establishment's faq and learned the do's and don'ts but that hasn't given me a very good idea of exactly what to expect. I realize there is a fair amount of sex occurring within but is it an orgy. Is there a proper way to signal to strangers what I might be into? Is doing things in public areas forbidden or is that part of the charm?