Apply to EVERY school in your interest that has a drama AND vocal program. Audition in both the music school as well as the drama department. Prepare a nice "scene" with a soliloquy for the drama department. For the Vocal, they will tell you what they require but be prepared to sing something in English, as well as something from a theatrical production, and you almost ALWAYS have to sing something in Latin. prepare at least 3 pieces. if they like the tape you send them, they will have you come perform for them. I’ve been there, and it’s scary – but I was successfull and I got a big Vocal scholarship!!

Good luck dear…
References :

Get contacts, make friends. Don’t burn ANY bridges behind you (lots of people learn this the hard way!) You never know how many people will show up again and again from past shows you’ve done with them. So if you hate a director or fellow actor…keep it to yourself! Even one comment can come back to haunt you later if that person is now in a CASTING position! Keep up with your high school choir director, dance teachers, friends in shows, etc.

Keep going, don’t give up. You have to do this for years and years and really love it before it becomes a career. If you want to get your equity card, do auditions for equity shows and get your points…but keep doing community theatre until you get your equity card. It is good experience.

Have fun! If being onstage makes you light up and feel like you are really alive…people will notice! It takes years to become an actor. But if you love doing it…it will all be a growing time! Never feel like you’ve "arrived"…have an attitude that is teachable, and keep learning things and always thinking how you can improve your performance. Think of small details about how you can be better as a performer!
References :
A good book to read is "Audition" by Michael Shurtleff.
I’ve been doing this for 10 years, and now I’m a voice teacher and actress.