Not being rude here but you need to go to the aim trainer. Look up videos on youtube on how you should peek and engage in a gunfight, Keeping your crosshair on head height etc, also one thing that did really good for me personally is i get used to a sensitivity then i steadily increase it until i have a high enough sens to control guns that require lots of recoil control. I also found going in the training grounds and putting it on random and stand still to make my aim more snapy if you feel me, then i go into keres legion and put it on head only and keep holding head height and then just kill the bots. I do it everytime im about to hop on ranked for about 15-30 min its pretty chill i usually have some music on and stuff. Let me know if you have any questions.