Hello, I studied a BTEC in photography (and passed!) and we were always told the basics of photographing fireworks is that you need tripod and the longest shutter speed available to you, without turning the sky to anything other than black. I'm afraid you'll have to experiment on the shutter speed though, as without seeing the lightness of the sky on that evening I cannot guess. Definitely don't try a fast shutter speed though, as you'll find yourself hitting the shutter and missing quite often.
I'd also recommend photographing fire, but using a very fast shutter. Looks really interesting to see it frozen in time.
Good luck!