I want to join the ATC (Air training corps) when i am 13?

I live in the uk so you have to be 13 to join anyway forgetting that. I am getting teased and my dad said that he is going to hate taking me to the ATC next year because i was watching my brother go to his mates and i said to dad he looked out of place because he didn't have his uniform and i said to dad he didn't look out of place with one thing and my dad said what and i said height and my dad said i was giving the boys the eye and i am being teased and when my dad said about taking me to the ATC next year he said though my brother (as in my brother the girl who is writing this) will be there to keep an eye on her does that mean that my dad and maybe my mum does not want me to get a boyfriend yet or until i am at least 15 and whats the best age to get a boyfriend i don't want a serious or mature relationship just a fun and harmless one is that alright? or is there no such thing plase help me i don't know what to do and i don't want to ask my parents