scotch.io has some more advanced tutorials.
egghead.io Namely, they have a course from the creator of Redux on how to use it.
There are a couple of people on YouTube who do React tutorials and get into more advanced topics like Free Code Camp, or you can glean vague information from developer seminars from AirBNB, Netflix, etc.
You can search for React articles on publications like Medium or Full Stack React. The official React blog is great for keeping up on updates.
A lot of React is all about ECMAScript, so I'd find a few resources to refine your grasp of that.
And as Mikey Lee mentioned, I'd highly recommend searching for React projects on Github and backwards engineering functionality you're interested in. HNPWA is a great site with YCombinator Hacker News clones done in various languages - they have a few React stacks built with GraphQL/Apollo and whatnot. And React.rocks doesn't update much, but they have a few interesting app examples.
Finding case studies from sites that switch over to React is an excellent option as well. Modern Tribe has a decent breakdown of their production of a React/Redux Wordpress theme built on the WP API.