Video of yours truly officiating

[justacoach]

I won't speak to your on court performance because you have been provided ample advice.
I want to remind you there are aspects of improving your officiating skills that do not require an actual game.
Near the top of the list is use this forum for the valuable resource it provides. The offseason is a good time for looking at the historical archives contained here.
You can immerse yourself in the rules and case book at any time. Find or ask about digital versions that can be run from your smartphone.
Become fully proficient about the rules and your projected confidence level will be greatly enhanced. Having great court presence, backed by solid rules knowledge, will overcome any perceived concerns as to your age.
Practice the proper mechanics often and in front of a mirror when possible. Sharp presentation of signals goes a long way toward making a good impression.
Find a mentor who you respect. Have them critique your games and guide you through the political situation of your local area.
Watch as much quality officiating as you can. The 2 minute summaries at official.nba.com give a wealth of info about controversial plays, videos and explanations that will show you an advanced view beyond what you will get from your HS centric peers. Many things will be at a variance with NFHS rules and philosophies but still worthwhile for the analysis of calls.

Hope this helps