Why are you waiting till you are older? Start earlier, learn earlier, learn more, learn faster, fail earlier (when it's less expensive), succeed earlier (and snowball).
Although I have taught myself a decent amount, I always just thought that I would wait until I had a proper CS degree. Plus I don't have much free time. I'm working 40+ hours a week for a startup now, learning the environment and what it takes for one to succeed.
Well, that's great. In that case, here's what I think:
Always push yourself to do more and better work. Wherever reasonable, do the right thing the first time. I know this is hard, especially in a startup, but there are micro-opportunities everywhere.
I find that some people have this ability to stay laser-focused on a project. And some can't. I belong to the latter camp and what I do is whenever I slow down or procrastinate a project, I'd switch to doing something else. Maybe the context-switch isn't that efficient for productivity, but I'd find that over time, I feel more positive (having done work, real work), and even if I end up with a dozens of uncompleted projects, I learn things along the way and they usually help somehow, somewhere, later. But of course finish the core project.
And while I'm at it, here's something I wish someone else helped me realised much earlier: learn good presentation, writing and documentation skills. (Perhaps you already do them very well, in that case, make it even better. Challenge yourself).
There's a few visible folks on HN who are very young and seems to have achieved amazing things, perhaps drop them a note and see if they have any advice?