Really well done for your level of experience. I was only dreaming of game dev at your age. Congratulations on your first game jam submission.
I thought your game was pretty good, but felt a little bit floaty and slow to respond. Spend some time playing with your velocity, acceleration and friction values. There are thousands of platformers out there so you really have to nail satisfying movement to stand out from the crowd.
Once again congrats and keep making games! I have only recently started making them again but wish I never stopped!