Is this question for hosting or attending?
Attending:
1. Requirements is likely money and Redemption cards.  It is best to be in contact with the host for housing, food, and other essentials.
2. There is typically not a minimum age.  Just be able to read.  Again, the GA State host is the best person to ask.
Hosting:
1. Rob makes all the final decisions on who hosts.  However, I believe he likes for people to have experience "under their belt" before hosting large tournaments.
2.  There is a minimum age to host a tournament.  15 with adult chaperon, and either 17 or 18 without an adult chaperon.
I hope that answers all your questions.