Giving away a piece on the third move is probably a good place to start assessing where you are going wrong. After your opponent has moved, always ask yourself what was the purpose of their move? Is (s)he threatening anything?
On the plus side, you developed your pieces early. Many beginners start by just pushing pawns randomly but you made two reasonable developing moves (at least, they would have been if it hadn't cost you a piece). Piece activity is very important, and in the opening you are striving for the initiative.
Keep plugging away at it... the more you play, the better you will become. Try not to worry so much if you lose a game. We learn far more from our losses than from our victories.
i have been playing for a good while i ahve played with other friends of mine on yahoo i am not that good but i cant seem to win 1 game can you plz help me find out where i go wrong i think it might be in my opening move but i am not sure thank you