Your country is in protection during the first 100 turns. In protection, your country cannot be attacked, but some options (such as the public market) are not available to you. You really only have to worry about three pages while you're in protection:
# PURCHASES
# BUILD
# EXPLORE
If you decide to build farms or indies, you can use the private market (located on the PURCHASES page) to sell food or military units to get money.
You should use the BUILD page to construct buildings. Buildings allow countries to take advantage of their land.
http://wiki.earthempires.com/index.php/Buildings
Countries generally decide which buildings to construct by picking a strategy and going from there:
http://wiki.earthempires.com/...x.php/Category:Strategies
Considering that you're starting late, I would recommend the Commie Indy strategy or the Rep Casher strategy.
Once the majority of your acres are filled with buildings, you should use the EXPLORE page to gain more acres.