Shooting fireworks is counter intuitive. It’s dark, you need to bump up your ISO (no, keep it low) and you need to open your aperture (no, stop it down to f11 or further). The only part about shooting fireworks that seems to fit is you need a slow shutter speed (3-4 seconds). AUTO on your camera won’t get you there unless it recognizes the scene and changes your settings appropriately. Some cameras do have a special scene setting for fireworks.
The other requirement is a tripod. You cannot hold your camera still enough without it. It also helps to use a remote. If you don’t have a remote, set your timer exposure to its lowest setting. Time how long it takes for the firework to travel and explode and push the shutter button that many seconds ahead of the explosion. This helps because when you push the shutter button, the camera moves ever so slightly. Using the timer features gives it a chance to settle back down before you open the shutter. Click on the image below to view my most recent images.
