I'll give you a small hint I use, if you're nervous about meeting new people. But you'll have to be careful with it in an interview situation: when I'm meeting new people, if their appearance reminds me of someone I know from somewhere else, I think about how easy it is to get along with that OTHER person, and somehow it relaxes me more. You just need to be careful you don't get too casual if your compare them with someone you know very well
Also: if you need a 1 second pause to think of a decent answer, then by all means take it. It's better to pause and think about what you're going to say, than blurt out something that might hurt you. Just don't pause too long
Be early to the interview location.
Don't chew gum or food.
Keep your hands out of your pockets before the interview, it may make them sweatier than they already are.
This is the other thing some people forget when in an interview, and I think it makes them more nervous: an interview is as much a chance for you to size the EMPLOYER up as it is for them to judge you. Whose to say you aren't interviewing at other places, and are deciding who is best to go with? May not apply quite as much with this kind of role, but don't feel like all the attention is on you. You can always ask THEM questions too, like how long they have been operating (either as a business, or in this particular branch), if they are family owned or franchise (if it's not already obvious... you'll look silly asking a Starbucks that Q
). Having questions will show that you aren't a stunned mullet when put in a situation that turn many into a frozen deer in headlights.
Further to the whole handshake thing: when you do shake their hand at the end of the interview, if you are still interested in the job at the end of the interview (remember you're judging them too!), then SAY you're very interested, and that you look forward to hearing back from them (I'd also ask what timeframe to expect to hear from them).
And just keep in mind... an interview isn't the biggest thing in the world. It will be the first of many, and at worst, if you don't get the job, you'll figure out what to do better next time
It's all learning.