How do I advance in composing?

Produce your compositions. Learn Logic. Make demos. Find a student film or video game to add your music too. Release it on SoundCloud and share with the world.

Jessica,

Ben is right, but let me expand a bit. You need to produce your compositions into a format that can be released or shared, that is pleasing to listen to and that clearly reflects your intention with the composition... a well produced sequence or a recording with live musicians (if it's possible). The type of composition may determine what is the best way to demo it... and of course your budget is a factor.

I've worked long distance with a composer from Connecticut for nearly 10 years who sends me his sequenced compositions for my advice, for me to record some live elements, and to mix a final version. Today he does many jobs, from commercials to corporate videos and short films. Perhaps there is a local experienced professional near you or that you can trust... someone that won't charge you an arm and a leg and can help you get started from the standpoint of helping you identify your strengths and weaknesses while you learn to produce on your own.

Where you live is not as important as where your contacts are. It doesn't hurt if you're in a city that has high volume of production and great demand for composers (New York, Los Angeles, Miami, Nashville, etc) but then you will find tons of competition as well. Competition is good because it forces you to be on top of your game, but it also makes it harder to find work.

But mostly, like Ben said before me, produce your compositions and share with the world. Let yourself be heard. There are many composition contests out there. A lot of the sample production companies like East West and others have regular contests for aspiring composers who use their products. Once you get some experience and refine your work you can start looking at the professional networks that seek compositions regularly for TV and film. There is work out there.

Good luck

Israel