This is a pretty good attempt for your first time with a new program
Theres a number of things you need to work on through. Firstly is how fluent the motion is. At times you've used 3 frames in a movemet when 5 would make it alot smoother. It causes it to jerk which is rather distracting. Fpr example the Z's just appear and disappear. You could work in an effect so they burst like a bubble or float off the screen.
Secondly you need to look at the frame speeds. Between it sleepig and flying it just randomly pauses which looks awkward. Also when the speech bubble shrinks theres a long pause on one frame. The Zs are also a lil too fast in my opinion.
Next up is the physics of the motion. If you jump in the air your arms move at a different speed to your body which causes a delay. They aren't glued in one spot. Try adding a bit of movement to them.
Overall you've got the drawing part ailed. The horns look great and the wings are nicely created. The shading could do with some improvement but that comes with time.
Stick with it and work on your aimation and i could see you doing well with emotes