I'm auditioning for America's Got Talent. Help, please?

I can only answer two of those questions. For how long do I preform for the judges, try and do your whole act. Make it short, so only a bit of the song, but long enough to show the judges how well you can sing. Just make sure it isn't too long that would bore everyone. And then if you make it, you would go on to the second round that would be wherever they want it to be, I think its in Hollywood, but I'm not sure. After that you keep competing until you are either eliminated or declared winner :D good luck, I'll root for ya.