With dozens of thousands of online resources, how can an aspiring programmer effectively choose what to focus on?

Don’t think of becoming a good programmer as a solo activity.

Surround yourself with people—both in person and online—whose skills you respect, who enjoy being frustrated by kinda the same things as you, but who have different backgrounds and experiences. (Echo chambers are boring. And stifling.) Work with them. Show off what you’re learning to them, and give them feedback and encouragement on their own stuff. As part of this process, trade recommendations for online resources. You won’t like everything they like, of course, because you’re not them; some of their suggestions will be truly awful. But then, so will some of yours.

Huh. This reads a lot like “With dozens or thousands of sources of online music, how can an aspiring music fan choose which bands to listen to?” Not a bad analogy, actually.