How can I get into musical theatre as a performer? Where should I look into for career paths?

It's started to be clearer to me that I want to work in the media/entertainment/theatre area, so I'm moving away from sports since it wasn't a passion. I was never involved in sports; I was a once in a while viewer.

I'm currently a PR intern and stage management intern, I'm enjoying what Ive gotten to learn and the hands-on opportunity that I've been given. It is a bit of writing though, so it's not terrible. But, I also want to go back into singing and music, specifically in musical theatre. I want to be a performer, but where do I even start? I've never done acting or dance and I'm a little rusty after not having choir class for 2 years now.

I plan on finishing my communications degree since I'm graduating a semester early. I've looked into the institute of American musical theatre, but I would need an audition for dance and acting. Should I go for a program or outside classes that offer all three components. I'm debating trying to apply for the page program at nbc after I graduate or other companies with a page program.

I have a semester and a half left, so I plan getting involved in clubs and hopefully getting an internship with a media/entertainment company, although I'm not the best at cover letters.