the audio is a nice choice, clear and charming
the backgrounds are nice on the eyes and good choice of warm colours, characters look nice on them
The "what you need to work on":
storywise, its a short, there isn't going to be much story.
however i had no idea that the character was late to class, perhaps it would have helped if the teacher was pointing at a clock to help enforce that.
There was weird frames where the colour of some characters go lighter or darker ? which makes it seem abrasive and look like mistakes.
Some line work wasn't cleaned up 0:08 so just take your time to clean those lines (as all the other characters don't have that issue)
But yeah, draw more inbetweens and keep at it!