Get to know your neighbors, local businesses, make ties to people. Attend city council meetings or whatever similar opportunities you have to get involved in minutiae. Pick an issue you care about like education, parks, bike lanes, whatever, and approach advocacy and learning like a hobby. The more people get engaged with face-to-face networking or organizing, the more the city is empowered to change. A lot of the real or perceived random violence and intractable social problems are really predictable outcomes of racist and impoverishing policies and habits.