At the beginning of the game all of this will be easy. Copan is in its prime, resources are plentiful, and its government is stable, making most actions quite simple to accomplish.
However, the city’s bounty isn’t limitless. Each resource has a Decline track, and when you place a Court tile to generate it, you cause the resource of that tile’s type to tick down by 1. When a resource reaches a critical level, it becomes more scarce, generating less than before. When a Decline track reaches its final tier, that resource has been exhausted and can no longer be obtained at all!