I think the fastest way to grow is to have your code reviewed. If you're not in a professional software setting then making a pull request to an active project with patient contributors will probably be your best bet. Find an open issue for k8s, docker(-cli), figure out how to fix it, open a PR and I would try to preface it with a "this is my first PR, I'm very open to critique" type of intro. With any lucky you will find someone who can gently (or maybe not so) nudge you in directions of better quality code.
Best of luck on your journey!