There are LOTS of groups and forums to explore here. I particularly recommend the active, relaxed, freewheeling Hang With Friends. Texas Heathens is worth a look too; and Writing to Congress offers inspiration on ways to respond to our "unpresidented" political landscape.
Groups don't clutter up a "timeline" or "news feed" page; some of us are members of many dozens.
And I keep discovering things through the "Latest Activity" in the lower right of each page. (Mobile view: menu, Activity.)