If you are planning to learn some programming language or framework you can give Koans a try.
A kōan is a story, dialogue, question, or statement, which is used in Zen practice to provoke the “great doubt” and test a student’s progress in Zen practice.”(Wikipedia)
I don’t know who started the metaphor, but I think it’s a good analogy, and I really like the Koans that make me think, though some are a bit mechanic and actually easy to see the answer.
The way it works is you clone a Github repository that has implemented failing test cases. Then you fix the code implementing functionality and filling in the blanks, getting the tests to pass one by one. Koans are helpful in understanding concepts and getting familiar with the syntax, and they are also a lot of fun. Though are not the definitive way to learn a language they help a lot.
If you want to get an introduction to some key concepts in React try this React koans https://github.com/alexlbr/react-koans