Thanks for invite but I, actually, didn't learned React on the professional level, I prefer Vanilla ES6. The good part about React and why it suck less then other frameworks is that at least by reading any examples I could instantly understand what approximately they do, when I was reading Angular-based code, I had no idea what it was doing.
Nevertheless, React IS JavaScript and I always recommend to learn your tools and languages you use on the highest level first before using and learning any frameworks. In case of frontend I still would suggest to use simple, plain vanilla JS and master it, with the help of some libraries of course. React is just a marketing, it is not better, safer, faster, cleaner. You can do the same without React. Modern JavaScript is very powerful and with combination of general software engineering and architecture patterns and principles you have maximum flexibility and simplicity.
I would recommend those resources:
I still would recommend any software engineer, even beginner, to try himself as a framework developer because:
Other answers here will guide you though the next step on React itself. I, personally, didn't liked official documentation.