NRFD,
This actually might be a pretty interesting avenue to explore. You'll have to be a little cautious with this because if you offend girls by accident or come off as creepy/stalker/etc. then you might hear about it from your boss should they decide to call about you.
Ree:my name is Ree...that's me in the dp....if I tell you where I got your contacts from,you won't believe
Girl:...where did you get my contacts from
For that reason, Ree, I wouldn't recommend this. It's so easy for a girl to be creeped out by this and go with something like "Hey <Pizza Place> Mr. Manager, I got some text messages from NotReal so I think he grabbed my number when I ordered pizza last night. You may want to think about whether he is a good employee or not."
That aside, I would talk to these girls like any other because you never when or where you're going to meet a cute girl and you have an advantage of having a time constraint. So, here's how I see things playing out; comment on how cute she is, make some small talk, deep dive a little if possible, and then use your time constraint;
You: "Listen, Katie, I'd like to keep talking but I have a few other orders to take care of and I'm under the gun. Let's swap numbers and continue another time?"
Her: "Totally! Here, it's XXX-XXX-XXXX" or "Sure. But don't you already have it from my order?"
In the latter case I'd probably still have her type it in your phone. If she doesn't because you already have it then that's still a "yes" to text her.
That's the bonus of having a legit time constraint. If she's enjoying talking to you (and because you only have a few minutes to talk it's likely she will be) then it will seem very natural to grab her number because you can't stick around - as a side note, that shows responsibility, social awareness, and confidence which are all very attractive. The only other pitfall to watch out for is you don't want to develop a reputation as "that pizza guy who hits on everybody." It's college, girls talk to girls and word gets around. Keep these things in mind and you might just find yourself having an interesting semester.
-Richard