Hello, I believe 3 do's of talking during an interview you must,
1. <em>Show respect to your interviewer. </em>You must not be rude in anyway, don't roll your eyes at them, make faces at them, nor be sarcastic to them.
2. <em>Know the job, and the requirements for the job.</em> You won't get accepted for a job or whatever you are doing if you don't have the requirements for it, make sure you know what you are getting yourself into and you can handle it.
3. <em>Be prepared to answer standard questions. </em>Your interviewer may ask questions like, how many jobs you had in the past, or why did you get fired from any other jobs, be prepared to answer questions like these in a understandable way, you can't just say "I was fired because I wasn't working" so always be prepared.
I hope this helped! If you were talking about a different kind of interview, then just comment it down and I'll try to help you with that. Have a great day.❤