Treat the interview as a professional matter. You never know if you will make a connection that will benefit you later in life or in your career!
Whatever your state of mind during the interview, it will show. If you are enthusiastic, you will perform better. If you are uncomfortable, your distress will show; if you are preoccupied, you will come across as uninterested.
Before you start an interview, know exactly what you want to say.
Prepare your questions and rehearse them. It's best not to stray too far from the topic at hand and bring the interviewee back to the center if they run on or go off on a tangent.
Know the background of your interviewee. This means to come prepared to impress the person you are interviewing by being familiar with their job or research or current problems in the field.
Don't consider anything you say as "off the record" simply because you say it is. Say only what you want and keep confidential information confidential.
Establish how you want to be identified.
--Adapted from https://www.apa.org/pubs/authors/working-with-media (2021)