Clojure is one of the easiest languages to learn. You need to know very few concepts to become productive in it. I get co-op students very 4 months at work and they generally start doing useful stuff within a week or so.

I wrote a conceptual starter guide a little while back ( https://yogthos.github.io/ClojureDistilled.html ), that covers all the basics that you need to know to get up and running.