Tony’s suggestion is a great one- if you haven’t encountered the Handel Harp Concerto yet, then first: consider yourself lucky. Second: get your hands on that harp part!
Although the Handel is on the rather easy spectrum of harp concerti (depending on which edition you use) in the repertoire, it may be a little tricky to conjure up in a week and a half. Sure, S.M. (curious to find out your name, also…), you could learn the notes in a week and a half easily- but to really obtain a strong, even tone without buzzes and with proper technique, that could take quite a while longer.
Perhaps you should try one of the Naderman Sonatinas. While they have very basic chord structure throughout all seven of them, they can be quite showy if played correctly.
Hope this helps, good luck at your audition!
-Steve