Laura, I suppose on-line covens are okay, you could very well learn from them. But a real live coven or Pagan group is much better.
You give your location as the USA, well, that is a very large area! You are old enough to join The International Pagan Federation, HQ in Florida. (Address on Google). Or you might have a look at witchvox.com it has list of covens and Pagan groups, so there might be one near where you live.