Learning the Right Things
With so much happening so fast knowing what new tech to learn next can be difficult. Where should you invest your time and energy? What if you spend ages learning the shiny new framework and it's gone within 2 years?
There are a lot of trends and a lot of new-fangled things do come and go. How do you spot the ones that are going to stick around. It's not easy - you kind of have to go with the flow, not swim against the tide (2 water based metaphors in one sentence, tut).
In front end development there are currently a few big JavaScript frameworks - Angular, React and Vue. It seems obvious to me that none of these are going away any time soon. Which do you choose? It really doesn't matter. Learning one in depth, finding its powers and limitations, will help you learn the others or other future technologies.
If you're really not sure where to turn I'd focus on core learning. In the front-end world, learn plain JavaScript. With ES2015 and newer versions than that emerging there's still plenty to take on and perfect. That knowledge will always be useful.
I guess my short answer would be to favour the evergreen HTML, CSS and JavaScript over associated tech like Pug, Sass, TypeScript, etc. As the core technologies get better over time these current convenience technologies may one day not be needed.
One word answer. JavaScript. :)