Welcome to the forums.
To get coins, you need to build houses connected to your roads, first that will be huts. After 5 minutes you will see a sign over the huts indicating you can click them to collect money. Then the timer resets and you can wait another 5 minutes before collecting coins from them.
Building houses will give you population, but this population is 'used' by any production or military buildings you have. If you hover over a production building in the building menu, it will show how many population it requires. If you hover over a residential building in the build menu, it shows how many you will gain.
I would advise you take a look at our wonderful
Guides Section. Especially this
Beginners Guide to FoE
Good luck and have fun!