They're gonna make me sing the Tiki Tiki room in the school & my voice is not good :(?

practice is the key not watching a video. are you aware that in the videos they are not actually singing at the time? nope the songs are recorded in a studio under the creative controls of the producers. the do little tricks to enhance her voice and make the song POP. almost all live performances pail in comparison to the recorded versions for that reason. now back to practice! all professional singers warm up prior to performance well most anyway. you need to learn to sing the scales 1st. work on them till you can do them all in one breath. next hold the notes longer and build your lung power. raise up the scale by a key. all of this will bring out your voice both tone and strength.