Depending on what your interest in theater is, I always recommend working on plays. It's a great way to be introduced to the field, and also a great way to be seen by agents and representation. I'm also a great advocate for studying acting at a drama school or a college.
“People who don't read seem to me mysterious. I don't know how they think or learn about other people. Novels are a very important part of our education.”
“I don't think my wife likes me very much, when I had a heart attack she wrote for an ambulance.”