To make a city grow, you have to build farms and other improvements with workers, then click on the city. This will open the city screen, where you can choose which plots to work. Since you only have a level one city, you can only work one tile. choose a farm tile, and your city will grow. Keep in mind that a city
will not grow when producing workers or settlers. If your city grows too big, then your citizens will start to riot because of overcrowding. To fix this, provide them with some health buildings, (like aquaducts) also, you can use slavery, which is unlocked by the Bronzeworking tech, to kill off part of your population to complete a building or unit. This will, however, make your city angry with for 10 turns, but less so than if it was overcrowded.
Roads are used to trade resources between cities (like if one of them is an excellent mining city with copper near it, connect it with roads to other cities to allow them to use that copper. Also, roads allow your units to move twice as fast along a tile that has a road on it.
To create your own state religion, research one of these techs: Meditation (buddhism), Polytheism (hinduism), Monotheism (judaism), Theology (christianity), Code of Laws (confucianism) Philosophy (Toaism), or Divine Right (Islam). to switch between these religions once you have these techs, go to the top right toolbar in the main screen. Click on the icon that looks like someone praying, and choose your religion. Sometimes other religions that you have not researched will leak into your lands if an AI discovers them first. You can also do this will the other AI's (NOTE: It is sometimes a good idea politically to become the same religion as your most dangerous or powerful rivals, so they will have less incentive to invade you) The world screen is the screen where you do all your actions such as moving troops, choosing things to research, ect.
PS. If you have the time, read the in-depth article within this thread:
http://forums.civfanatics.com/showthread.php?t=165632