I'm just trying to figure out how to see my kills and deaths for the current match I'm playing.
If you are playing slayer, you can see how many kills you have by holding the back button. Your kill count will be the number next to your score.
If you are not playing slayer, you cannot see your kill count.
In any mode, you cannot see how many deaths you have while the game is still going, but you can see both your kill and death counts in the score screen after the game.