Hey Peter,
Glad to hear that you're getting out there and performing for people! I hope that it was a lot of fun.
As to audience management, it is a very tough thing to focus on this early in the game. A lot of audience management you can learn from just going out there and performing. Another thing I use a lot to my advantage is just being relaxed. Try not to convey a sense of urgency or tenseness. If you are nervous or tense, then a spectator can pick up on that. People have a hard time taking magic in the way we want them to experience it if your hands are shaking too violently for them to see that the coin has actually vanished (Not saying that you do that. I've just been there lol).
For example, every Friday I do one trick as many times as possible for as many people as possible. This benefits you in a lot of ways. For one, it gives you a lot more practice time on that particular trick and helps you get better at doing it. The more productive time you have with something, the more you will learn about it and understand the workings and everything behind the curtains that people don't think about right off the bat.
By doing that, we accomplish number two, which is making yourself more comfortable performing the trick. It helps you feel more confident in your own skill because, hey, your practicing the trick more often, and if your practicing and performing it correctly, chances are very likely that you're getting better at it.
A great number three, which I'm sure most will agree with, is you're getting performance time. That, in my opinion, is the best type of practice you can get. Yes, you are doing a good thing by practicing and then showing the magic to people you trust first. But once you are confident enough to show that magic to people outside your comfort zone, that is where you will get some good learnage.
Number four, which is definitely my steeze when it comes to doing magic, is that I can analyze the situation that has just occurred. I can see what played well and what didn't play well. What did they seem to like and what didn't they react to? Were my angles right? Did they seem happy? If they caught something (which will happen sooner or later, I promise. Don't worry, it's not as bad as you might think), why did they catch it? Did I flash? Did I not use good patter to compliment what was happening? There are so many questions you could ask yourself. Just doing that can help yourself learn to do magic "better" for spectators. If you apply what you've learned from past mistakes, you can continue working towards that "perfect" magic moment that we all strive to create.
Now I must say this. Seeing that you are 14 years old, I can almost bet you that if you continue to do magic for spectators, young and old, someone will not take you seriously. I don't know if that's happened to you already or if anyone has brought that to your attention, but it will happen. I think that anyone who has done magic as a teenager has dealt with that conundrum. That brings me to this point: It is more difficult to manage spectators if they think it is a joke or do not take you seriously. It will get easier as you get better and you get older, but it can be tough in certain situations. I must absolutely recommend performing as much as your heart can bear. It will help you get those nerves out, and it will help you look and feel much more confident in front of an audience. A sense of confidence and relaxation can really help spectators relate with you on a better level. Not to mention that it will help you learn how to control situations and how you want the magic to be perceived.
I hope my rant helps you in some way. I have no magicians in my town to hang with, so I've gotta get my thoughts on subjects out sometimes. In the future, please keep posting questions or PM me. I'd love to hear about how your performing goes and what you're working on!