I'm learning Rust and reminding a bit of C as I'm working on some side - projects with systemd. I always believed that the only way to learn something is practise & repeat.
So I thought that I need some exercises. Found great service for that: https://www,codewars.com. You choose languages you want to practise and start coding. By completing Katas you earn points, honor and some other stuff. Gamification here - I like it!
Every Kata provides some tests you may use, so TDD is in place. You may also create your own Kata and publish it.
Try yourself. You may find me here: https://www.codewars.com/users/docent-net