Singing in school show help with performance?

I'm singing in my school show (Stars in their eyes :D) and normally wouldn't do this kind of thing but my friends in my form were listening to music and we were singing along and they said I had a great voice & said I should enter the show. I eventually decided to enter (with Grenade by Bruno Mars) and people came up to me and asked me to sing for them (you wouldn't expect someone like me to have a nice voice) and when they heard me they said things like "woah you actually are really good". So now I'm entering the show with a solo but I don't want to look an idiot should I add dance moves or something? Or will just me and a mic be fine? I'm not bothered about winning but it'd nice to p the auditions. :)