How do I sound? (also, music suggestions please?)?

You aren't trying to SOUND like Ella Fitzgerald are you? If so, it's not working. She is among one of the greatest vocalist that ever lived with a distinct easily recognizable voice, so work on your own version of her arrangement. You better try practicing with the accompaniment as well since you want to make sure you are familiar with what the accompaniment sounds like, and if it is in the same key you are singing it in. And speaking of same key, you have problems staying on pitch, and part of that I believe comes form trying too hard to be hip and jazzy. Ella was hip and jazzy, but she also had incredibly perfect pitch and could smoothly going from one note to another, no matter the interval.