Glad you're on our forum.
From what I've heard, polyamory is most often defined as multiple romantic relationships, where everyone involved is informed about all of the relationships, and is okay with it. So, MMF and FFM vees/triads are certainly one kind of polyamory, as is everyone living together, but there are many other kinds of polyamory. What would not be polyamorous (but rather another kind of non-monogamy) would be if it was "just about sex" or if emotional connections were avoided. Poly people can, of course, have some "non-poly" situations in their life. Some polyamorists are also swingers, for instance.
I would say don't be in a rush; take your time to learn all about polyamory, and find out exactly how to describe/explain what you're looking for, both to yourself and to others.
Sorry to hear about your divorce. I hope it can become a new doorway into new ways of living.
Love means never having to say, "Put down that meat cleaver!"