How to calm my anxiety around girls?

Depends on what: the anxiety is about. Are they now Teens and you have concerns? Or are you anxious with all things? Go to a counselor and find out your pattern and diagnosis. They can best suggest treatment solutions like therapy and/or medicine. good luck.

I am guessing that: you are a male and feel anxious around women but might like to be dating. Talk w/a trusted male friend and you will find out that he has had anxiety also. You can speak w/a trusted woman friend or relative and ask them for some tips. It's fear of the unknown but don't worry, nature takes it's course. If the above is not helpful, a clinical psychologist can be. Peace and good health.