One of the funner parts of beginning to play chess is choosing your opening repertoire. It's usually best to start with just one or two openings at first, and to learn them really well, in fact to become an expert in those openings. There are numerous openings to choosefrom; slow positional openings like the French Defense, or exciting tactical openings like the Ruy Lopez and the Queen's Gambit, and hyper-modern openings like the King's Indian Attack. However, all of these openings are based on just a few opening principles. If you first learn these principles then you will be able to understand why certain openings are good and the ideas behind them.
Principle one: Occupy the Center! This is the very basis of chess theory: control the four squares in the middle of the board. One way to understand this is to think of the center of the board as the upper ground in a battlefield. When your pieces are in the center there more squares they can jump to than if they were on the edge of the board, they can quickly get to any part of the "battlefield", and they control the vital area that your opponent's pawns will have to pass through to get to the other side of the board and queen. If you remember just this one idea, to control the middle of the board, then your game will immensely improve.