My first thought is going for walks around where you live. If there are green spaces along the way that’s even better. You can turn it into kind of a workout where you do longer and longer walks, or the same length but a little faster each time.
It’s a good way to clear your mind, it also never hurts to be active.
Drawing. It’s seen as a skill reserved for an elite few, but in reality anyone can develop it. I learned it at school from lessons very similar to how Peter Gray teaches it (see this book for example on the Internet Archive).
All you need is a pad of paper, a few pencils and an eraser. And then sketch away, plants, people, landscapes, characters, whatever you want to explore.