I won some concert tickets through a local radio station, i'm not sure how i get the actual tickets......?

the dj said that i get them the day of the show at the venue, but how do i know that they have them for sure. is there a place online that i can find out? the concert is june 5th, gwen stefani, at the xcel energy center in MN. i'm also wondering if a school id will work to pick them up with because i don't have any other kind.........