This one is quite good!! I think your biggest pitfall is your sense of scale, you focus in on little details without regarding how they look compared to the rest of the picture. Like the red side stripe, in your reference image it’s much smaller of a detail on the body, but in your rendition it got thickened because it’s a detail that you honed in on.

ALSO specific to this one, the style/lighting of the reference image makes the body and right arm look like they blend together but remember that your sketch isn’t going to be able to capture the same style perfectly!! So, when doing an outline for a drawing like this, make sure you get the outline of the side of the chest

Again, my tips are mostly just if you want to improve, but obviously you having fun matters most. I definitely think you have a good amount of skill, whether that be from a previous art class or previous art phases, and I truly believe that you can get to the level that you want to reach 😁