0. Watching this [0] Fireship video to get the “big picture” on the language.
1. Reading the “Noteworthy Differences from other Languages” [1] section of the manual, if your language is on the list.
2. Then, if you're hurried, read Learn Julia in Y Minutes [2], or otherwise read the official manual [3] in order, skipping sections you're not interested in.
In case you're interested in scientific computing specifically, you can start from Chris Rackauckas' course on Parallel Computing and Scientific Machine Learning [4]. And if you don't have a straightforward application to test Julia on while learning, I would recommend doing the exercises available in Exercism [5], which are well-made and provide access to awesome mentors.
As for books, Think Julia is pretty good imho, even if it's a little bit outdated.
[0]: https://www.youtube.com/watch?v=JYs_94znYy0
[1]: https://docs.julialang.org/en/v1/manual/noteworthy-differenc...
[2]: https://learnxinyminutes.com/docs/julia/
[3]: https://docs.julialang.org/en/v1/manual/getting-started/
[4]: https://www.youtube.com/watch?v=-lJK92bEKow&list=PLCAl7tjCwW...