No, not at all.
You should not touch a girl's bra without her knowledge and permission. If you are not close enough to a girl to ask her how to touch her bra, then you don't need to worry about it.
Getting breast cancer has nothing to with wearing a bra.
wear a padded bra
10
Your only option is to guess the girl's bra size. If you are not buying her a bra, you don't need to know her bra size. Try to find out something that's important to her instead.
No it does not. It's not good for them to sleep with a bra on though.
You call a girl with no bra on by her name. She is no different than a girl with a bra on, she is a person who made her own clothing choices.
No.
Whether to sleep without a bra is a personal choice and can depend on comfort and individual preference. Some people find it more comfortable to sleep without a bra, while others prefer the support it provides. There are no significant health risks associated with sleeping without a bra, so it's best to choose what feels right for you. Ultimately, listen to your body and do what helps you rest better.
Around the age 9-13, a girl will get her first bra or training bra.
There is no "normal" bra size. It varies from girl to girl.