Contact your city and find out where the fireworks locations will be. Perhaps they'll have some suggestions re. locations, or they may even have a place in the park to have everything. We got married in a county park in PA, there was an old home on the grounds that was open to the public which we used for the reception, and we had the wedding outside. It was lovely! And because none of us really drank much, we had a lunch time ceremony/reception w/no alcohol (Park Law :) - we figured if people wanted to drink to celebrate, they could go out after, and we didn't have to worry about expense - or embarrassment!
Congrats!