If you don't centralize your government and create a real nation at home then you can't colonize other land becuase

Other lands are taken over by other nations

Towns and small farms are usually for land, lakes, rivers, and seas.they also produce other food, like crops.it's also where animals are, where we get our meat.large plantations normally have forests, where crops are grown for sale. (similar to farms)plantations have larger fields of crops.our wine, sugar canes, and fruits come from plantations.