Don’t stress it if things aren’t going well at the fireworks display.
Put the camera on the tripod. Frame the scene in front of you. Set the camera’s mode to Aperture Priority. Dial the f/stop to 5.6. Raise the ISO to around 400.
Take a couple of shots. Look at them on the back of the camera. Too bright, then drop the ISO to 200 or 100. Not bright enough, raise the ISO to 800 — though this is usually not the case. Take a couple of shots and repeat.
The key is to not get flustered. You can do it!
Kathy Adams Clark 
Kathy, thanks so much for this well-timed post! Excellent advice when I needed it most.
I started out with the settings you recommended, and I was grateful to have guidelines of a good place to begin.
One thing I noticed was my camera struggling to focus on the dark. So I switched auto-focus off and got even better results. At 400 ISO and 5.6f, the exposure was quite long. Is that exactly what you want?
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I’m glad the post was helpful, Cynthia. In another post I covered the autofocus issue. I focus on something like a building before the display begins. Then I turn off autofocus and image stabilization.
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