Drew Carey's Improv-a-Ganza?

So I just found out that they are going to have 3 live shows of Improv-a-Ganza on june 23rd 24th and 25th. I'm 14 and I really want to go because I have watched those guys preform together since I was little and I love Jeff Davis :). So my question is how old do you have to be to go to one of the live shows (with my parent)??? Am I old enough to go??? I'm really confused because I heard that you have to be 21 but on one episodes there was a 17 year old in the audience (she yelled out her age) and on another one there was an 11 year old there and he got to go ON STAGE! Ever since IAG started I have been waiting for this opportunity to go and now I don't know how old you have to be!!! Any help will be appreciated! Thanks in advance!!! :)