This is a cute first entry and has a neat premise and some interesting melodic ideas. I think there are a few points you could work on:
- Dynamics: Right now, the song feels a bit cluttered. Try to emphasize lead parts and make accompanying parts a little more quiet.
- Textures: A quick and relatively effective way to improve how MuseScore playback sounds is to install sound fonts, I particularily like "Timbres of Heaven". In the long term, it's probably a good idea to learn basic usage of a DAW, but for right now, if you want to focus on improving your composition skills first, I think going for sound fonts is a perfectly fine solution.
- A little more rhythmic variance would be nice, and maybe some other background parts.
Anyway, congratulations on your first jam submission! You should be proud of yourself for getting your song out into the world. Keep it up!