Although it definitely could use a little bit of work, I respect trying to go out and make something! Heres some tips if you plan on doing GB Studio in the future:
Use #65ff00 (or bright green) for the background of your sprites. It removes the white outline that most of them have.
Maybe go into the settings and tweak some of the default platformer settings. Theres a lot but they can change gameplay drastically.
I think its fine for a first project, though perhaps you could work on it a little more? Hope this helps!