Koans
Whenever I start a project in a programming language with which I’m not familiar, I try and find “koans” to do in the language along with my daily work.
I’ll spend maybe an hour a day working on these until I complete them (assuming I’m liking the exercises and structure).
I think I worked edgecase’s ruby_koans when I first learned Ruby back when I joined Chime.
I found it by searching for “ruby koans”.
I couldn’t remember if it was this repo at first but then I recalled the “path to enlightenment” metaphor.
I personally found Ruby a very unapproachable language for how much “magic” there is – it just doesn’t resonate with me – but these exercises made me someone who can write (and read) Ruby.
You can find Koans in many languages easily with a search for “{language} koans”.
Sort of related: Code Koans.
Exercism
I used Exercism a bit. I liked it and was a fan of the experience but the exercises could be a touch too technically involved for me. I generally learn a language better on easy exercises and then separately learn how to apply the language in project work with it. Doing both at once slows down my high-level fluency because I don’t see enough language constructs as quickly as I need to to get familiarity.