A couple quick setting changes that’ll improve your performance.
Guide to Competitive Settings
Turning motion blur off will reduce blurriness making your image clearer when looking around
Turning on 3D Headphones will make it easier to hear where enemy footsteps are coming from.
If you play with keyboard and mouse I’d recommend changing the targeting sensitivity to 100. This matches your ADS (aim down sights) sensitivity with your normal sensitivity so you’ll have better muscle memory and will have an easier time tracking targets.