Use mouse to aim and move camera using Cinemachine

Hey Im trying to get a camera system which uses the cursor to move the camer while always beeing locked to the middle so i can use it for aiming (Like the Game Risk of Rain 2). I already have a movement and a way to rotate the camera (using Cinemachine) but the problem is that the mouse is not sync with the camera turning speed first of all and 2nd i want to use it to shoot so it gotta stay in the middle of the screen. Let me know if you need any screenshots! Thanks in advance