An overview of how to get started from scratch with Julia
Exercism assumes that you already have some knowledge about the Julia language to the point where you understand the basic concept of a function and know the syntax reasonably well. The Julia language website contains a regularly updated list of learning resources. This is the go-to place when looking for books and tutorials on Julia.
For examples on what to do with Julia as well as more specific tutorials, check out juliabloggers.com.
While Exercism itself only supports English at the moment, there are Julia resources available in other languages that you may find helpful as reference material: