first off...NEVER admit you are nervous, in any situation. it is a known fact that confidence, not arrogance is an extremely desired trait. I mean if you're about to have brain surgery, do you want you doctor to tell you he is nervous because if he f***s up you will die? NO...you want him to say RELAX...i got this. that being said...everytime I have EVER gotten an interview...i have ALWAYS been hired. and these are my tips.
1. you are indeed judge the second you walk in, so dress professional. I once saw this kid interview the same time I did cept I had business apparel and so did he, except his shoes were converse. I mean come on kid, this is not highschool. needless to say, I didn't see him during orientation, I'm almost sure his shoes were a huge factor.
2. give a firm hand shake, I think this is huge, you don't wanna squeeze too hard, but a good firm handshake to show you are not week.
3. Don't say "UMMMM..." when asked a question you are unsure about, this shows you are not sure, again...showing lack of confidence.
4. Be prepared ahead of time, by this I mean, the most common questions I have been asked at an interview that stump most people these:
describe a time when you had a disgruntled customer and what did you do to fix the situation.
you're definitely gonna get asked about your weaknesses, just make up something minor and don't say something like I HAD TO TAKE REMEDIAL MATH IN HS SO PLEASE DONT PUT ME ON THE REGISTER CUZ I WILL DEFINITELY F*CK SH*T UP! say something that is generally not regarded as a weakness but in your eyes is, something like, Oh I tend to be too trusting of people sometimes...some bs like that.
5. Confidence Confidence Confidence. they make ask you things that at the time, you might not be sure you can do, but do not, under any circumstances give any clues to these insecurities. remember, even if you don't think you CAN do it at the time, be confident that you can, because you will be trained, and you WILL be able to do what is being asked of you.
6. When they give you the opportunity to ask questions, do so. like, what is the starting wage? can we pick up extra shifts? things that show your interest in the company.
7. Finally (cuz this is the last one I can think of) be persistent about it. you can ask, so I should expect to hear form you by so and so...? and if you dont...keep calling.
anyway...thats all I can think of...hope this helps...cuz I put effort into this answer damnit so it better hahaha!