I'd like to say I can help or offer advice, but my best quad is the blade nano qx 3d I got on sale and I mostly fly airplanes.
-First and most importantly, don't let anyone tell you age makes some kind of big difference. Yah, it makes a bit of a difference (mostly in time), but your much better off starting at 12 instead of in high school. (Just take my word on this.) And, as long as you are patient and make sure everything is set-up mostly correct, you should be good!
-Second: I assume everything you have flown so far are stabilized (non-racing) quads, so I recommend practicing in a simulator without stabilization before you invest in, or at least before you fly, a full racing quad. (A good free one usually suffices)
-Third: Expect the worst. Be prepared to loss everything to a simple crash and have to start over. This (likely) won't happen, but it is easy to get overly upset over one broken prop. (I gave up for a month because of one.)
-Fourth: Have replacement parts and tools, but don't go overboard- Watch your budget beyond the essentials, and try to get only what you do/will need, not what there is a small chance of you wanting someday in a few years.
-Fifth: Find someone else in the hobby to work with if you have not already.
-Don't expect cheap stuff to be as good; Cheap alternatives are normally good and do as they are supposed to, but there are noticeable differences. I'm not saying don't try to get cheaper things, but don't get obsessed either and don't ruin an expensive frame by using a really bad flight controller that only saved you $2.
Good luck!
(I make no guarantees on my advice, I've never made or flown a real FPV racing quad)