Correct, Stacks is coaching at Templestowe College and an excellent teacher of the game.
Honestly, for an U14 rep kid, just shoot mate. Get a ball, find a rim, get a rebounder and just catch and shoot, catch and shoot. There are enough videos online to teach you correct footwork and action. So get the action right (video yourself then compare to those online) then repeat that action over and over again. And work on your off hand too.
There's a great Klay Thompson one talking about the "reverse waterfall", which I love.
https://youtu.be/i0FQd7v8efI?si=8ezsUAWD1BQSm7Kt - this is Goorj with first bit talking about teaching juniors how to shoot properly.
No "best" coach is going to make a kid the best. The kid can become great with great work ethic.