Politeness is essential in the teacher's office. Teachers are generally very kind. You must answer honestly what the teacher asks, and don't show off in front of the teacher. Ask the teacher questions prepared in advance at the right time. Of course, don't forget the main purpose of looking for a teacher, asking what to prepare before the second interview and how the results are. The general teacher may say that you should prepare for the second interview, even if the teacher wants to accept you, it will not be too obvious. Anyway, there is only one meeting before the second interview.
Go all out to find a teacher after the second interview.
This is my little experience. I hope it helps you. Good luck! -