I'm the CEO of the company that built Dolt. Dolt is a SQL database with git-style versioning. DoltHub is a place on the internet to share Dolt databases.
We think Dolt is an especially good way to learn SQL. Dolt is almost effortless to set up, contains real data, you can make write queries without fear, examine your diffs, and publish your work to the DoltHub community.
We wrote a blog post expanding on all those topics here:
Check it out!