Which school are you interviewing at? They're kind of on opposite sides of town, so if you want to stay close to either of them I'd give you different suggestions. But if you're planning to hang out in central Phoenix/airport area for a while, there's still lots to do.
There's lots of good restaurants especially in downtown, here's just a few:
https://www.thrillist.com/eat/phoen...x-restaurants-the-best-restaurants-in-phoenix
Matt's Big Breakfast and Pizzeria Bianco didn't make the above list but are some of my favorites and are really affordable too.
If you're looking for a coffee shop to hang out in, Lux on Central is my favorite but Songbird Coffee and Lola Coffee are also good options.
If you're the sciency type, the Arizona Science Center is pretty cool. If you like art/art museums, the Phoenix Art Museum is DOPE (and free on Wednesdays after 3). If you happen to be around on the first Friday of any month, you can check out the live music, food trucks, shops, and art exhibits on Roosevelt Row as well. (Art Museum has free admission, too).
I would check on what will be going on during the time of your visit, there's a number of food festivals and events that happen in the fall. Here's a good place to start:
http://www.phoenixnewtimes.com/calendar
If you're into sports/outdoorsy stuff, that's not really my area of expertise so I don't know what to tell you, haha. But I'm sure you'll find something!
Phoenix actually has a crapload of events and activities, you just might have to dig a little to find them. I hope you enjoy your time here, and let me know if you have any questions!