Wow, good luck. Most roles like that require all-black when working with the addition of something from the store. I'd say go long sleeves, semi-casual. Since it's Nordstrom jeans might be ok but if you have any I'd stick with non-denim dress pants or a plain skirt. Blazers or another formal jacket is a bonus.
These roles and stores hire almost entirely based on looks, so I doubt the questions will be major, an make sure to wear good makeup. Most people I know who had jobs ar such places got asked things about their school life, previous jobs, interest in fashion and trends, nothing too stressful!