Voice ,,,,AHHH!!! Help.?

My friend wants to enter to a talent competition. We are a trio btw. me and my friend wanted to dance. Well i wanted to sing originally but i got realistic. MY voice isn't good. Any of us isn't good. My friend is well let's say proud of herself with her own voice. We three sound like asians. I hate this, I'd rather dance but she kept on saying to sing, sing,sing ,sing. Cause that what cool americans do and whatever ****. (no offence) i don't idealy have a good voice. i sound flat. My friend which wanted to sing so much couldn't even hold a nice pitch she breaks and continues the pitch. And it's not really that nice and i imagined it infront of the whole school. I told my friends to quit and just do it in youtube but my friend she WANTED to do it NOW. i got irritated. My friend chose this horrible song. Dynamite-Taio Cruz. I hate this song. i know it's pop and all party but i don't wanna sing that for a talent competition. I just want some cool song which we don't have to puut many pitches in. I wanted to at least change the song because the lyrics of the songs are too simple. and the chrous fills in the empty song like 4 times. i get breathless. PLease help recommand some songs (which are new) and how to make my voice better, when i try to hold a pitch it'll go all squeaky and break off in ugliness!