What to Wear to a Job Interveiw

So I got two call backs for job interviews neither is my dream job; but any job is better then nothing at all.  So now I have to decide what to wear?  Neither is super professional so is a polo and nice dress pants OK?  I haven't done a resume in years either I don't have a clue where my old one is!  I know I'm horrible!  I just have always worked for my parents so why anyone would hire me for experience is beyond me at least I'm willing to work extremely hard to prove I can do anything that needs to be done.  Any advice would be great!  How can I WOW my interveiwer?  What should I wear?