You can sign up for whatever you want to shoot in. Being a junior means you can also sign up under either Amateur, Semi Pro or the Divisions Series. Juniors and Ladies are a bonus category forvthisevthat qualify to help drive participation by up and comers like yourself and Katie Harris types.
Jake Denno is currently leading the amateur and Junior race and I'd bet money he wins them both because he is a boss with those open guns. That means at 14 years old he will reel in $5,000 in each division and a pair of Stag 3G rifles. That's over $12,500!!! I would also bet money that 90% of the pros including myself will win less money than Jake in 2012 Jake and/or his Dad saw a great opportunity and are capitalizing on it. So you might think about Shooting TI or HMO or any of the smaller divisions next year if the same structure is used.