React.js Fundamentals is a free course, offered along with another course (ES6/7 for React, $45) and some upcoming paid courses in McGinnis' React.js Program. The Learn React.js: The Basics course ...

Multiple courses take you deeper into Javascript, including "Redux with React JS: Learn Redux with Modern React JS" which is an enormous favorite of students, who rated it 4.8 out of 5 stars.