He should always be prepared to talk about his first interest in music. His first time touching a piano. Why he choose piano (which may have been his parents forcing it at first). What other instruments he plays. What is favorite music is. Details about whatever piece is performing now (maybe spoilers on what he is practicing but not yet performing). Ideally he should listen to modern music so he can connect to kids by talking about something popular today (maybe even play a piano arrangement of it).
Those are the basics that he should have an easy time talking about. If he unexpectedly wins an award he didn't expect to be in competition for he might be speechless, but for the above the answers should be easy.