To get better, there are many factors involved. As for the best guns, I recommend the Fal and MK14. I think the Fal is the best for close range, while the MK14 is great for long range when used with M61 rounds.
@@ibrahimmahmoud2591 To find your sensitivity, you can start by experimenting with the in-game settings. Many games have a practice mode where you can adjust and test different sensitivity levels.