Commerce cities should have libraries, markets, universities, grocers, ...
Production cities should have forges, factories, often aecuaducts, ...
Coastal cities should additionally have lighthouses and sometimes harbours.
All cities should have granaries, courthouses, barracks.
If you go to war often, most of your cities should have theatres and coliseums.
To make your game easier, play a civ/leader that provides economic benefits, via traits like financial, organized or philosophical. Genghis is kinda hard to run a solid economy.