I don't know Julia, but Clojure and Go use two different programming paradigms (functional vs imperative). They are two different ways to think about programming. Which one you pick depends on what you feel comfortable with.
What I'd recommend is to find a free, online course or tutorial for the languages you'd like to learn and just give a go!
- https://exercism.org/ has free courses for many languages contributed by volunteers. quality can vary per language
- https://www.codecademy.com/catalog proprietary but has a free Go course of a few hours to get your feet wet
Otherwise, Python is quite the easy language to learn first. It's nearly as if someone wrote pseudo code on a napkin and said "this should be able to run on my PC".