Free and low-cost leisure activities in Portugal

An acquaintance of mine who is a local resident living on Pico on a very limited income recently received a whopping €60 parking fine on Pico near the Euroapotheca and EDA in Madalena where entire streets are being remodeled and the taxi stand was moved across the plaza next to the important shops. For your information, an average salary on Pico island is just €500 a month. The taxi drivers are now preying on people who look foreign and call the police to issue parking fines even if those spaces remain empty for the entire day and local cars are being parked there unmolested. What a ripoff without properly announcing the change. Tourists beware, especially those driving rental cars.

I think this is a great question and I hope more people respond.
I haven't moved to Portugal yet, but I was thinking what I might do and here is my partial list of inexpensive things to do:
Tennis, learn a musical instrument, learn to paint, walk or join a hike club, volunteer a few days a week, beach trips, learn to cook, read, cinema, fishing, camping, bicycle, library, photography, amateur acting, pet mind, dog walk, chess, body board, surf, snorkle dive, canoe, badminton, visit/explore local towns, star gaze, visit produce market, teach dog tricks, bird watch, go to museums on Sunday when they are free, join a local class in something, play walking football.