Juggling, unicycle. The circus crowd is a nice crowd to hang with and is usually not about the money whatsoever.

There are some groups in my city who organize non-profit training meetups together, multiple times a week. Usually in school sport halls, when the kids aren't there. In the summer, people meet in specific parks together. The biggest juggling convention in Europe (EJC) is basically a juggling festival with thousands of visitors every year, each time in a different country. Not free, but non-profit as well. There are lots of smaller conventions like that everywhere. If you ever feel like learning to juggle, feel free to come and join us!