Good thread, interested to hear how it turned out. Like many said, meet with several brokers. Really you need to look at it as you're the one interviewing them. How much support, training can they provide?
When I was at my first brokerage there was many favorites.. "protected neighborhoods" for listings.. don't buy into any of that. You need to realize that you are running your own business, and you're paying a large chunk of what you earn to your broker. Make sure you get some kind of value from that split.
Another thing to take note of is broker splits. Typically large name companies will have 50 / 50 splits. Then you work your way down, and typically get less training with less of a split.
Welcome to real estate.. it is very fun. Learn from people who are successful, and those who are not. You will find real fast that some agents sit around the office and wait for the phone to ring. You need to figure out how to make it ring.
One last note.. do not let your age discourage you. I got licensed at age 24... not many people took me seriously because of my age. My 1st year I did $1m.. this month I should do right over $1m :)
Good luck -- you're in the right place to learn! Be a sponge and soak it all up.