I just landed a staffing manager position and thought I could help you.
Common questions I got were:
1. Why sales?
2. What do you think is the day to day routine of a staffing manager?
3. How do you overcome obstacles or frustration in the workplace?
Those are just some of the questions that stood out to me that I had to think about.
I would dress professional, think before you speak (listening is key), and smile. A hiring manager or the owner will pick up on your abilities just by talking to you.
I hope this helps. Best of luck.