Hi, my name xxxx xxxx and I am a student at xxxxxxx High School in xxxxxx, xxxxxx.
I am fine with any interview time you can manage to find for me (except school hours of course). Can't wait to meet you!
If you haven't heard back after a week, should one resend? I've had e-mails 'lost' (which seems impossible) or take a week to arrive at their destination (which also seems impossible).
Yes, I had one applicant this year whose e-mail went into my spam folder for no distinguishable reason. Feel free to resend after 10 days or so, with a note explaining that it is a resend.