Worked a lot as a child and barely played. Missed out on lots of personality development. I have more free time now and I want to play, but I don't totally understand how.
I was told when I have something fun to do, learn to fail the marshmallow test and just immediately eat the marshmallow. I feel paralyzed. I'm used to playing only if I'm invited by someone else to play, and I want to play more when I'm alone.
So far I sometimes draw and read a fun book. Both usually make me anxious, but they bring me feelings of accomplishment.
If you want to learn rhythm you could always pick up some drumsticks and a practice pad and practice some basic rudiments and techniques. Bass Guitar is also pretty nice for this, I found it pretty easy to at least pick up and play, but it challenges my rhythm abilities a lot. I think they best strategy for any instrument is to learn to count rhythm, and play with a metronome as much as possible