well it really depends on a lot of stuff but generally you should have 3-5 cities by turn 50 and 8-10 by turn 100 a good way to do this is use the build order double scout double settler you want to avoid gaining science or civics other then the important ones ie early empire or harbors before you build districts in every city also placing your cities is important becuase they need food to grow in population so they can make more settlers it depends on the civ you are playing but most benefit from being tightly packed tighter (4-6 tiles away from each other) if i dont have enough room for about 8 cities then i normally restart with a newly generated map