Sometimes, it’s just easier to watch someone show you how it’s done. You can find all kinds of educational videos about nearly any coding-related topic nowadays: ex-Googlers sharing solutions on coding interviews, YouTubers livestreaming their coding marathons, and even programming veterans showing you how to troubleshoot a specific error in any language you want.
EdX is another leading online-learning platform that is open source instead of for-profit. It was founded by Harvard University and MIT in 2012, so you know that you’ll learn about cutting-edge technologies and theories. Today, edX includes 53 schools. You probably can’t go wrong with the free Introduction to Computer Science from Harvard University.