What to write as an e-mail to work full-time at the place I intern at?

I have been interning at this place for 4 semesters now, which is equal to roughly 12 months in total, almost a year. I have had 3 different mentors, which means I know and have the approval of the head people there. I have been working there via the director's invitation since he is content with the work I put out. I got used to the office; I know what to do and how to do it. I am completing the tasks quickly without any mistakes, and I do enjoy working there. I am a third-year student, gonna graduate in 8-ish months, and I want to start working part-time or full-time as far as my courses allow me to, to make some money/extra income. However, I am stressed about what kind of email to send. Has anyone had any experience like this? What would you suggest? How did it turn out? Thank you!!!