Hi again Sparrowhawk !
Here is some more info you might find useful
Your dad can be your adult mentor. A NAR or TRA membership is useful for the insurance it provides - but might not be a requirement depending on the circumstances.
You can fly your rocket anywhere the law allows. You have to check your local laws. California (for example) has a lot of restrictions and most folks have to fly with a club at designated launch sites to be legal.
You have to have the permission of the land owner. Don't make the mistake of going to a park or baseball diamond and flying without permission. You or your dad might get a ticket if rockets are not legal in your area.
At a club launch, ask about the rules. The club might allow you and your dad to fly with them without a NAR (or Tripoli) membership. There might be a "Launch Fee" at some clubs. >>> Hint - you will get tons of help if you go to a club launch. You will find the most helpful and friendly people in the world at organized rocket launches.
I think flying with a club is your best option!!
TTW = Through-The Wall fins using Lite-Ply Plywood. This is a very strong way to attach fins. I get all my plywood and most of my body tubes from
Balsa Machining Service (I met "Balsa Bill" in 2017 at NARAM 59 - he is so nice!!!) The 1/8" plywood he sells is super-light weight, the lightest I have ever found, and much stronger than balsa.
Check-out the "Apogee Aspire". This
rocket kit from Apogee Components can go supersonic or fly over a mile high depending on the motor you use. Look at this kit to get some i
deas for your own rocket. Tim Van Milligan
(owner of Apogee) is very nice and he has a TON of
helpful Rocket Videos on YouTube.
JLCR - Jolly Logic Chute Release. Think of this as an altimeter that releases a rubber-band.
[Jolly Logic website here] The rubber-band holds your parachute tightly closed, and your rocket
(with the parachute ejected by the motor ejection charge) just free-falls... until it reaches a low altitude. The JLCR releases the parachute at a low altitude
(you can set it for the altitudes you choose) and it works like dual-deploy but without black powder. Many folks call the JLCR a
"game-changer" and one of the most innovative rocket products. I used a JLCR on my Jr L1 - M1 rocket. John Beans
(owner of Jolly Logic) stands behind his products with excellent customer service.
Here's a picture of me with my Tripoli M1 rocket and my mentor - Tripoli TAP Gus P.