Sabina CutiedeTahlia It's just that people your age rarely wear chastity belts other than with their parents as keyholders.
Eh, I would say it is highly unconventional for minors to be wearing belts to begin with. With very few exceptions, those that do and have their keys held by an adult are victims of abuse. Not something I would recommend to people.
I would recommend you to keep the keys to yourself until your 18th birthday. After that, you should have the freedom to figure out what you want your keyholding situation to be like and to seek out people to help you in that.
Until then, a timed keysafe might be the best tool to avoid temptations to neglect your chastity goals. Be sure to get one that can be easily destroyed in case of emergency, though.