How to put together a job portfolio if it is my first job?

I'm 17 a senior and live on the south side of Chicago. I interested in working as a Sales ociate at Forever 21, Giorgio Armani,Walgreens,CVS pharmacy,etc .What things do i need to show the manager for my first job interview?Would it be good to bring an Educational Resume,Educational Portfolio, or what are some other ways to get hired quick.