We’re all very tense when it comes to interviews. After all, everyone likes making an impression, and interviews are the best place to do so. The most important thing to do is to be punctual. Not only will it show your interviewers demonstrated interest in the job, but it will also allow them to understand that you aren’t a tardy person. It would be best if you also came prepared: research the company well, as well as the job in question. You have to show how you align with company values to make an impression with the interviewers, and that's where the research comes into play. You should also try and practice beforehand - have a friend help you, and try to tackle some common interview questions.
Lastly, your interviews should never be one-sided! Take an active interest in it and treat it like a conversation. Ask them questions! After all, interviews are not just about them getting to know you; it’s also about you getting to know them!