First trip to swinger's club: What to expect?

A friend of mine is curious to check out a particular theme day (the "plus size" day) at a local swinger's club (Club M4 if you're near the Toronto area or have direct experience). She's asked me if I could come with her, just so she has someone there. I've never been to a swinger's club, and while I'm poly and generally sex-positive, I don't consider myself a swinger. I think it could be an interesting learning experience, but I'm wondering if anybody can give me some thoughts on what to expect. They say that the bar and dance floor are closed for their daytime events (which this event is) and they have more of a social vibe crossed with a play party. Do you think new-and-just-curious-people would be an issue? We're unlikely to want to participate in anything at this time (although you never know for the future), and would mostly be just scoping out the vibe and atmosphere.