Yea u can use kovaack 2.0 on steam. It’s actually very useful but u can also use aim lab which is free on steam.
Practice, practice, practice, warm up before games.
Make sure to keep your crosshairs up. There are markings all over the maps at around head level to make it even easier. If youre already looking at the height youll need to shoot at, your reaction time will improve significantly. Also lower your mouse sensitivity so you have to move your mouse arm more, and use less of your wrist. It seems counterproductive but it will make you wayyyy more accurate and help you gain muscle memory faster. Your sens should be low enough that by moving your mouse from one side of the mousepad to the other you can do a 180 and thats it.
If you crouch and don’t move and shoot you’ll hit a lot shots also if your mouse has a software you can you download it and set the mouses material it’s on to what your using for better movement (AIM)