Men should not have to wear bras if they do they are either fat or obese or morbidly obese in that case they should be concentrating on losing weight not sur porting there breasts.
Yes even if they have no breasts they will get used to it by the time they do
Ask your mum...she probably wears a bra.
If she thinks your not ready,ask about training bras or sports bras,the work just the same.