Preciate it. I started off playing a story mission or two tryna get the hang of the controls and settled on 5 sensitivity and the default control scheme. just keep in mind that lower sensitivity allows for more precise aiming which is important in this game. headshots are key so the best place to practice is in the SWAT playlist where there are quicker respawns, no shields, and magnum or battle rifle starts. you will get smoked early and often but who cares, stick with it.
in any playlist with any weapon - aim high, do not stand still, and don't panic - if you get outgunned so be it, hats off to him, but if you take your time and land your shots you can win any battle
for example, this clown caught me reloading, I miss a snapshot, and still get a perfect cuz he panicked and I just jumped back and kept my shots head level
Here's the others from each week that I had the game btw. I've basically tried out every weapon on every map, and I know what to go for and what to avoid - I suggest you do the same