Lit off a firework now facing possible misdemeanor

I lit off a stupidly bottle rocket, unaware that the city that I live in has laws against fireworks. I’ve never lit off fireworks before in this area. Long story, short neighbors called the police. The police showed up. I admitted to lightning off the bottle rocket was very cooperative. I showed the cop my package of bottle rockets. This was all on body cam. The officer told me that I am in no immediate trouble, but he would have to fill out a report to send to the city prosecutor. Then they will decide from there whether they press charges. It is a misdemeanor with up to $1000 fine and or 90 days in jail. I am worried, what actions should I take to help protect myself in this situation?

Location: Washington state