There’s always a nice breeze at the lake, so dig that old kite out of your garage and get down there. Prime spot is by the Gift of Wings kite store in Veteran’s Park, where you can buy a kite if you need to, or just watch the pros with those crazy trick kites.
Practically every parish throws a summer festival for fundraising, and there are usually multiple festivals every weekend. There’s free music of the cover-band variety, and lots of great people-watching. (And beer, but of course that’s not free.)