What to learn, I can not decide!?

Question

JavaScript

Hello, tell me what to study.
Unfortunately, I can not finally decide on what to do the main bias in the study. You can't learn everything at once. I want to be a professional front-end developer, now I know html5, css and Javascript basics. But for quite a long period I can not master anything specific. I take jquery, json, sass, less, ajax and I can’t really learn anything, because there is also Angular, which many people praise, reactjs, etc. Please direct me, advise what will be in demand for a few more years, if, of course, such assumptions can be made.

Answer 1

go slowly, things like Angular and React are much easier to learn when you already have a certain level in JS, namely a solid understanding of the basic concepts. And so it will be just poking on the spot and not productively spent time.
Learn JSON? rave. Realize the need for formats like JSON/XML/etc. Purposefully teach less / sass, the same is not ok. Learn CSS (less/sass/postcss are just tools that allow you to better organize your code), and not in terms of properties/selectors, but in terms of layout approaches (BEM, MCSS, etc.). Well, yes, learn what DRY is and why there was a need for tools like less / sass at all.
Don't learn AJAX, learn HTTP. Then it will be easier to separate the implementation from the overall concept. Stop mindlessly saying "make an AJAX request", let's say "make an HTTP request".
In short, the direction is simple - when you have a more stable foundation, then you can proceed to higher-level things.