I had the dream of a poly household under one roof and it has come true with about 15 years of work. It is possible, but takes some time to create something sustainable. I believe this kind of cosen family is the way of the future actually. Not necessarily poly, but many peoiple in one house. You can read my bllog to find more nitty gritty details about my tribe.
Starting to date is a greart place to start
poly people seem to use okcupid mostly as a dating site. You could do a tag search for "dating," or "dating sites" or maybe "okcupid" and see what comes up.