I got a call for interview at party city, and if things go well then it will be my first job. But to make sure everything goes well I want any advice of how to do a good interview. So any help would be appreciated.

Read up about the company and study their history and so on. If you get a good chance to mention some of it during the interview, do it, it will help as they will see you as interested in the company which is always a plus.

What are your good sides?
What are your bad sides? (try to spin them into something positive like I'm X that's why I do Y to overcome it or whatever)
What do you have to offer to us/why would you be a good employee here?
Don't be a zombie; be awake, alert, keep a straight back and greet them with a nice firm handshake.

Speak clearly, dress nicely, get rid of any piercings and wear something that covers visible tattoos at all times, be direct but polite, shake your interviewers hand, don't ramble, don't interrupt, try and present yourself in the most positive light possible, use real life examples if possible (like if you say something about having a good work ethic use an example from school or if you volunteer and present it well), don't bring up anything negative unless the subject is broached first and then spin it the best you can, stay off facebook or any of those, TURN YOUR PHONE OFF,

Or just dress like a zombie; with Halloween coming up they may appreciate your initiative!

I think Freddo nailed it.

Present yourself well and don't try to be something else or pretend to know things you don't.

Also, when asked something, like for example, are you a good leader, say yes rather then "I think I am". Try to follow up with a reason or two on why you say yes.

Good luck with the interview and let us know how it went.

Give a firm handshake, ask questions (What will the job be like, do you have any comments on my qualifications, and so on), be polite, dress well.

Just remember that your greatest weakness is either:

A) Kryptonite

Chocolate

C) A Crippling inability to answer vague questions

But really just make sure to ask a lot of questions. If this is just some sales or customer-facing position at Party City (which sounds most likely) then it's not going to be some huge interview. One major thing is post-interview. These low positions want to hire someone who is enthusiastic or wants to be hired so it's your job to call them back and ask if they filled the position left and tell them how much you appreciated the interview and are looking forward to hearing back from them. If you don't call them back you won't get the job.

Also dress nicely.

This is very good advice for a career position, but this sounds like some highschooler's part-time job.

Get a good nights sleep the night before. Be at your best.

Where i work now as a "seasnal" employee, i had my interview during work as i had been a temporary for 90 days.

As a result of pushing for seasonal by talking to human resources and supervisors, i was very comfortable in the interview, the interviewer knew me by name and it made everything simple and easy.

My advice is be comfortable, but professional, as you dont seem to have the luxury of knowing your employer beforehand as i have.

Dress for the job you want, not the job you're getting, obviously this doesn't mean go in wearing a clown costume, though this is party city? No! Dress nicely.

For good jobs later on it helps to make early connections, this may not happen for many many years down the road, but those you go to school with will remember you, and if you remember them ask them if they can vouch for you.

Never walk off the job, if you don't like a job put in your two weeks notice, many employers will not hire those who quit without notice. This may not apply now, but it's good advice nonetheless.

And everything else has pretty much been covered.

Pretty much of all of the above is solid advice. A line I like to keep in my back pocket, and have used successfully a few times when asked "What do you know about XXXX", XXXX being the job/industry/product sold/etc. Response is "Well, I don't know much to be honest, but 2 years ago I knew nothing about XXXX and I can tell you everything you need to know about it now". XXXX being the previous job of course.

What Freddo said in the beginning.

Oh and keep eye contact, makes you seem confident and [censored].