I think this might be a great time when you can take something simple and overengineer it! When I was a little younger than your age, I made a whole "virtual c

I think this might be a great time when you can take something simple and overengineer it! When I was a little younger than your age, I made a whole "virtual currency" that could be moved around by typing numbers into text boxes, just to get some experience using PHP and MySQL. It didn't ever do anything useful, but it was a fun exercise, and more importantly: the fact that I was pursuing one of _my own ideas_ made me more interested in working hard on it. So my advice would be to pick something simple you like, and then apply all the principles you've learned to it, even if it doesn't always make the most sense. This is just a learning project, so my guess is that some regular rules don't apply!