Exercism (https://exercism.org/) are running a 12in23 challenge this year and this month is Functional February!
I think that this video is a great high-level introduction to functional programming with discussion and code samples of the following concepts (and of course they talk about Elixir as well!)
- Functions as first class citizens
- Pure functions
- Immutability
- Pattern Matching
- Recursion
Certainly worth a look if you’re new to the ideas - the Elixir track is excellent