Who should I contact if I want to become a pro singer/actress?

callie=] asked: I’ve been dreaming of performing for people since I was 6, and so far, I’ve played Dorothy, Annie, danced in the Nutcracker, and sang in my elementary plays, plus a few other things… I want to become a performer, so are there any companies/agents my family and I could contact and look into? [...]

how to get a choir to harmonize well like pros?

positive plus asked: i am also learning how to teach choir and will want them to sing like pros