Great!
I just want you to know what you’re getting into. Julia’s docs are, by now, into hundreds of pages, I forget where the PDF link is, I think around 400 or 500.
I don’t know where you want to start, there seem to be (unofficial?) translations of the web page (which is very much smaller and manageable):
I suggest asking other translators, as I’m not up-to-speed, e.g. here, what they do:
I also like to point to:
https://en.wikibooks.org/wiki/Introducing_Julia
That’s unofficial (and rather small I see already over 160 pages), and I believe Wikibooks wants/welcomes translators. They (any) translations, will quickly get out of sync… so I would start with whatever is most stable, the language syntax, and mention core packages that will be around.