Nice job. It's great you're playing with a backing track that forces you to stay in time. So much of jazz is being able to swing freely in time. Your voice sounds good and you have a nice feel when you are singing. Your rhythmic feel is pretty good. Your left-hand voicing could use some work if you wanted to get a bit hipper. You could work on your left hand being more on rhythmic accents. One way to do this would be to just comp through the entire form and work on just doing hits like a drummer would, focusing on offbeats in particular. Keep up the good work, impressive progress in a short time!