I've had several student teachers over the years.

I learned to give them a rules and expectations sheet at the beginning. I hand it to them, and then we discuss it the following day. Any questions, suggestions, or comments are shared and discussed thoroughly.

I gave her a folder with a map of the school, names, important reminders, etc.

I made a small gift for her, including pens, pencils, a small mirror, hand sanitizer, post its, etc.

I gave her an area for her so she does not use my desk. That was major for me.

I had her share yard duty days with me. Good for both of us.
My last suggestion is to be clear about your expectations, and follow through with that. Introduce them to everyone at school, and have him/ her attend staff meetings. A student teacher could be a huge asset, or a great hindrance in your classroom.