Learn to ship.

Make something useful, even if just for you and maybe three friends. Ship that. Sooner. Ship it when it hardly works. Then iterate.

This will teach you all the good bits of "agile", some requirements thinking, pragmatic programming, and (if it's a web thing) some basic "how to maintain an app on a server" skills, all in 1 go. It's also all stuff that is super hard to learn from books or from too-experienced coworkers.