Hi Cherry!
I used to be a manager in the cosmetics dept at Macy's and was the one who gave interviews! They're VERY typical of probably every other interview you've been on. There really aren't any cosmetic questions (at least none that are standard in the interview...your interviewer may throw in a couple of her own).
The questions are very situational like "Tell me about a time when you made a mistake on the job, and how did you fix it" or "tell me about a time you went above and beyond your job duties for a customer"
They're very standard interview questions and don't worry about spending time thinking of a real answer, just make up a story, they'll never know
Wear business casual clothes, so nice dress pants and a blouse (no cleavage!), or a skirt and a blouse. This isn't the time to look trendy like MAC style, just dress business casual as you would for any other business type interview.
Do your makeup well, but not over the top. I'd really suggest to stick with neutral colors, and maybe a hint of color, but just make sure the makeup is done very well.
As far as not having any retail experience, that shouldn't be a problem. Macy's hires people all the time straight from high school that have no experience with anything. If your interviewer asks you how you think you will do in retail, tell her that you're very goal oriented and that you plan on adding on to each sale by pairing a lipstick with a lipliner and a gloss, or if someone's looking for an eyeshadow, you'll also try to sell them a mascara.
Just make sure to show your passion and desire to get into macy's and explore your opportunities
let us know how it goes!