Hello Nick, Welcome to TRF!
Here is what you need to know about High Power Rocketry in the USA for people under 18 (like you and me).
LIMIT = Single Use “F” Motor
There is a national law (U.S. Consumer Product Safety Commission) that says motors above ‘F’ power class, and all motors that use metallic casings (including reloadables) regardless of power class, may only be sold legally to those 18 years of age or above.
What this means is that you can use any “single use” F motor by yourself, but you can’t fly anything larger without adult assistance.
YOU CAN DO EVERYTHING BUT FLY-
You can build ANY size rocket you want - there is no age or certification restriction on BUILDING a rocket. You can then give this rocket to an adult to fly for you. This does not require you to be a member of TRA or the NAR. The adult has to purchase the motor, and is the flyer of record.
TRIPOLI MENTOR PROGRAM (access to high power pads)
If you are at least 12 years of age, you can join Tripoli (TRA) and take a WRITTEN mentor program test. Written test only - no flight needed. Successful completion of the test allows you ACCESS to the High Power launch pads at a TRA launch when accompanied by a High Power Certified adult member. With your TRA membership you will still need to fly/certify L1 when you turn 18.
NAR JR LEVEL 1 (automatic L1 when you turn 18)
With a NAR membership - 14 year old's - Build a level 1 rocket, and fly it successfully with the assistance of a NAR High Power Certified adult member to receive “Junior Level 1” certification. This converts to Full L1 status on your 18th birthday, no additional flight needed.
I am a member of both NAR and Tripoli. I passed the written TRA test, and last year I assisted my mentor with an N 10000 motor flight at the Midwest Power launch (photo below) . I will be 14 next spring and I am planning my NAR JR L1 rocket.