Welcome to our forum.
There isn't any easy ways I know of to find the type of venues you're looking for, you just Google "clothing optional" and see what turns up. Or you can Google "polyamory _____" (putting the State you live in in the blank). Perhaps there's a poly group in your locality and you could get together with them if they're holding social outings. If there are any swinger groups in your area, you could see if they have any non-sexual get-togethers and get to know them that way.
Continue to do some research, and have patience, as the right time and place will eventually arrive. Interacting with various people on Polyamory.com will give you some idea of what to expect.
Glad to have you aboard.
Love means never having to say, "Put down that meat cleaver!"