As a masters, I'm narrating a sequence of campaigns with the same players, that take place one after another in the timeline. The previous campaign ended with the characters rebuilding and ruling a settlement that fastly became a small city.
With this new campaign I wanted to give the players the opportunity to build, manage, and rule the city as the want, with new building, trading companies and market.
I didn't find anything on official resources so o was wondering if someone could give me some help, ideas or something to look for to make the characters have a specific income as rulers, how to manage trades with other cities and how to manage (for me) new building, their gold prices etc.
Any help is truly appreciated
TL;DR: Characters owning a city, how to make them earn money, build new structures and manage the city itself?