Hello.  I finished a game not too long ago and would like some pointers regarding the opening and how I could have improved my game.  As you will notice from the game, I lost.  If there is anyone that could illustrate what I could do to improve my general opening, that would be appreciated.

For starters, check your moves to make sure you're not giving away free material.  11...d5?? just gives away a pawn, while 13...f6 gives away two more.  Don't hang pawns.  Don't hang pieces.  Get solid there, then worry about opening principles.

Very true.  I clicked on the submit button and realised my mistake straight away.  I never thought out the position, the tactics, and the defence.  Plain passiveness.  Anymore pointers?

I agree with the previous comments.  When you were trying to move your queen to safety from the pawn on move 19, you missed Nxb4. If he wasn't planning on checkmating you right away, you would've been down a queen and surely lost anyway. Always watch for attackers before you move to a  square. At the very least, make sure they're protected so you could get the knight back for the queen. 

 Also regarding that string of queen moves, you are looking to develop yourself before your opponent so making three or four moves that your opponent can easily defend against is maybe not the best move. Also, always watch out for your king before you damage your pawn structure. Make sure it has a place to go.

I notice that you are both ranked a fair bit higher than me so if I've missed/misjudged something, please forgive my ignorance.

This is how u shoud play as black.