beginning game
Position after 1. d4 d5 2.c4 is called Queen gambit. White will give up the c peon for a central control by playing e4 ( if peons are exchanged dxc4) . Exchange is only one possible way for black , there are others more popular moves like e6 as Skewy has shown ( Queen gambit declined ) or c6 very solid move ( Queen gambit - Slav defence ) .
You don't rly need to know all of this , u made a logical move that can lead problems for black if u decided to hold to the c4 peon but u have played solid e6 after that which puts white is in a positional advantage but it's not so critical to decide the game at this stage
http://www.chess.com/echess/game.html?id=47571248
if you go back to the start of this game and press the next move button 3 times you will see me (black) pawn is up against 2 pawns
what should i have done (i moved already) to deal with the situation?