You are never more aware than during an interview for a new job that you are being judged. You may be aware of it because everything you say is being weighed and measured. The interviewer is trying to ensure that everything about you is appropriate for the job and their company.
The job interview can be a nervewracking, harrowing process. It is a necessary one. It doesn't matter if you are new to the workforce or are a seasoned veteran. The job interview is a thing you are going to have to get through.