Do your research first and ensure that you know where you are going and that you are on time. It is also important that you are neatly dressed and groomed appropriately.
Nerves are a normal emotional response during an interview. If you’re nervous, it is best to just be honest and tell the interviewer. Some interviewers will try to put you at ease by starting with some small talk. By all means use this to ease your way into the interview, but only if the interviewer initiates it.