Here are some sites I enjoy using

• Khan Academy
• Duolingo
• BookBub

Some things I do:
.Play video games
.Play card games (or board games if you have more than one person living in the house, however there are some RPG card games that only require one person, example: the Arkham Horror living card game.

.Reading: the site I mentioned above, BookBub, offers good deals on and free ebooks. Another thing is lot of libraries are connected to services like Libby, Overdrive, and Hoopla. With the first two services you can find ebooks and audiobooks through your local library's website/catalog, then with hoopla you can check out a certain number of digital items per month, they have tv shows, movies, ebooks, music, audiobooks.

.Watching videos on YouTube
.Listening to music
.Drawing/coloring
.Arts and Crafts, Pinterest is a great site to get ideas for projects to do, even just browsing Pinterest and pinning stuff to different boards on the site is fun in itself.
.Playing an instrument: this is a very fulfilling hobby. Currently I'm learning to play the ukulele

Baking/cooking: I personally love baking and making desserts, it's really relaxing and you feel good for doing it and get to eat something good.

There are a lot of virtual tours you can go on online, museums, national parks.. etc.