Personally, I like a guy that has a good balance of maturity and childishness. By childishness I don’t mean whining about not having their sandwich cut the right way, but being able to enjoy “kid-like” stuff and being silly while still being able to act mature enough to survive in the real world.
For example, my current boyfriend and I have a great relationship. He and I both love anime and video games, and often watch/play them together. We can be silly together, but he’s also mature and responsible about money, school, etc. He’s not perfect, but he’s pretty close to it for me. :) On the flip side, my first boyfriend (whom I dated when I was 14) was terrible; he constantly broke promises and got into trouble, never took anything seriously, and placed too many sexual expectations on me. I realize some girls are already interested in sex at 14 (sadly), but when I was that age it was the last thing on my mind!
That being said, you’re still 13, a very young age to be putting a lot of pressure on yourself to make yourself good boyfriend material. And, every woman is different; their wants and needs in a partner change with age and other factors. It’s good that you’re considering these things right now… that’s an indication of maturity, so you’re ahead of the game there!
It’s very important to have the “friend” aspect down in a relationship, like you seem to have, being able to talk to girls about their problems and such. However, most relationships also need a bit of chemistry and, well, sex appeal, to cross the bridge from friendship to romantic relationship. Being a shoulder to cry on is great, but if you’re looking for a girlfriend you’ll need more than that.