So anyone who has gone to a UDA camp knows that seniors with the technique/personality to catch the staff members' eye(s) receive applications to apply to work as UDA staff doing Poms/Dance team camps.
I'm really wanting to do this, but no one from my school has gotten this offer before (at least not that I know of), so I don't know what to expect.

I was wondering if anyone has applied/auditioned before, or know someone who has? What exactly is it like?

I'm not sure about the UDA camp you go to, but at NIU basically every girl who [was a senior] that did the level 4 lyrical got an app. But, if you aren't given one you can always get one from varsity.com/your local rep.

You will need to be able to pick up choreography super quick and be able to break it down.
Also be very solid in your technique, show personality and presence when you dance.
I also think there is an interview.
I was given an application when I attended (many years ago) and one of my students tried out, but flopped on picking up choreography.