Good composition but a bit soft, probably due to motion. You need a fast shutter speed to get good shots at the ice rink. This will mean a large aperture and, depending on the lighting, may cause the camera to report a low light condidion. What that means is that it cannot open the aperture enough to get a proper exposure. Setting a higher ISO will help but can introduce noise. Flash can be used if the subject is close enough (e.g. within 10-12 feet) but more than likely your subject will be too far away for the flash to do any good. A longer telephoto lens will get you "closer" to the subject but will also cut down the light coming through the lens.
As you can see, there are a lot of variables to consider. Each has its pros and cons. You have to work with what you have available and make the best of the situation.