Getting started with HTML, CSS, JS, jQuery and ReactJS to create my own websites instead of using Wordpress. I already know some basics of HTML, CSS and JS. :)
My tip: Search for discussions about jQuery on Hashnode and think twice if it is really worth to learn and use.
tl;dr: it was nice during browser wars, but is garbage in our modern world, as its only goal was to abstract away browser differences which do not exist anymore, today.