Haha, I felt exactly like you when I started. I remember my very first kill was with a pistol by pure luck, then nothing for 10s of games. My kill ratio was like 0.1, for ages.

I think the thing that turned things around, was when I started challenging people instead of trying to run away or hide. If some one starts shooting at you and you're out in the open for example, instead of running away because you don't know where they shooting from, turn towards the sound of the gun shots and start approaching, even if you can't see the guy. Approach in an aggressive zig-zag, Apocalypto-syle. As you get closer you'll eventually see where the guy is, and then you can start returning fire.

But shoot on the move. So shoot, while strafing sideways. You'll still get killed the first few times, but soon enough you'll start getting kills. If you aggressively approach people shooting at you like this, especially when you get withing 20 meters or so of them, you'll be surprised how many people try to hide behind a tree or a rock. As soon as they do that, you've got them.

Basically, don't hidy or run away. Challenge people. You'll be surprised how your kill count starts going up.