As a wise venerable old teenager, I can give you advice. My greatest wisdoms that'll keep you safe from anything in the world are.
Don't Spit Into The Wind
DON'T EAT THE YELLOW SNOW!
These maxims will keep you safe from anything in the world.
Well, if a girl starts attacking you, seriously, the best thing to do is just hold her, not in a loving way, a sort of 'keep away from me you frak', this will work and not ruin your cred because.
You arent beatin on a girl, you are restraining her, that doesnt hurt.
You are probably stronger than her (if not, run, just hope that you are faster than her)
This is ideal, because if you are running away, it looks like a friendly chase, like she wants you. Nobody can slag you off for beatin a girl, they will just nod sagely and say, 'and that is what the wise man did...'
PERFECT
Remember that if you are ever attacked by a girl. But if she is bigger than you or older than you by quite a few years. You may attack back, at your own discretion, I wont think any worse of you.
Any other questions that require an unnesesarily long wise answer?