Hmm... well maybe Timpani if you are playing percussion in Concert band (since you also have the marching band) in marching band maybe just a bass drum, since learning rudaments is... kind of difficult, you could also play bells or chimes, marimbas, or xylophone but I think they may be all treble... unlike timpani which is Bass clef and since you play cello
it's easier to just learn how to play the instrument then learn notes all together
and that's pretty sweet that you play cello
D