Emailing teachers and classmates is an important skill to have. The below links give some advice, examples and help. You should also contact Mr. Marshall for help.
Guidelines for writing good emails: Has examples of day emails as well.
What to include:
Clear subject line
Salutation - Dear…../ Warmest regards,
Detailed introduction: who, what, where, when, why
Questions you want to find out
Invitation for interview or meeting - give some options
Good grammar
No spelling errors
Polite/ formal word choice
Ensure your profile picture is professional