Not a class, but I'm thinking about buying a cheap clarinet and teaching myself. I recently learned that you can get one for under $100 new on Amazon. Those ones are probably really not great, but there's one that's around $250 that has decent reviews.
I've thought about taking some university classes just for interest's sake now that so much is available online, but I have practicum in January and will hopefully be starting a new job after that, so now's not the right time.
I've taken a few free online non-credit classes on Coursera. Indigenous Canada covers content that everyone living in this country should know. I found Understanding Violence quite interesting. It looks at violence from a number of perspectives, particularly public health.
I know several people who have taken ASL classes with Queer ASL. I think it would be good to learn to sign, but I'm not sure it would be a good idea for me, as I've had carpal tunnel syndrome several times.