I always found this way too clumsy, because you learn X but accidentally miss Y, and X becomes your tool of choice at places where it doesn’t really fits best or at all.

Javascript traditionally had NO good language guides, and this one looks pretty like the one you should read in advance. Other resources are either more library reference-like, very situative or for unclear standard, not exhaustive, or just stupid and wrong. I’ve read a language guide A to Z for every PL I used in my life (a bunch), and can say by skimming through few rough/key topics that it is definitely a good one. No offense, but my advice is to not apply your advice when there is a good guide. You’ll save both your own time and the one’s who will come after.

nowadays I usually refer to MDN docs and one of the guides like above when guidance is needed.