Oosik,
You need to totally rethink your city placement logic in order to get command of the game and turn it into a fun process of discovery.
Many people share the same misconception that you do, the required city placement might in some way be related to the shape of the 21 square x shaped thingie that your have picked out.
The real answer will not bother you when you step back and look big picture at the game.
There are three steps in city size <=6, <=12, and >12.
Your current approach is stuck on the idea that every city mus tbe size 21 or larger and that basically throws away over half your game. It would be impossible for any of you cities to reach size 21 without a hospital and if you play with the choices you have currently made you will never see a hospital.
Look instead to see how you might place every city to guarantee access to use 12 tiles of terrain. At the edge of the coast your cities will push out and gain you food, gold, and territory that will increase your score. Internally the cities will crankout shields to build infrastructure or unit that can transfer power to other parts of the map either by force or by transferring shields though disbanding in targeted cities.
The suggestion that I made for you to place dots on your screenshot to represent where the citizens are working will also help you to get a renewed perspective. Your objective in the game has nothing to do with placing big empty cities that do nothing. Your primary goal in whatever victory condition you choose to pursue has to be to harness as much of the resources and power as you possibly can from your start position and then to use it smack or cajole your neighbors into abject submission.
This was a strong map position for learning the basic skills of how this game is played.
If you take the starting save file for this game and back up to the beginning with a renewed focus, you will find that this sort of game is fascinating and fun and its quite likely that you will rule the world on the same model as the great Britannic Imperialism that shaped the history of our world for over 300 years.