Having trouble with a third person camera script

I have been following a ton of tutorials because I'm new to Unity and I feel like I've gotten the hang of it, but while making a third person script for a game I'm making for my collegeclass I ran into some errors that I'm not sure how to fix. The only thing I can come up with that's missing is a LookAt reference but I can't figure out how to fix that at this point, I'd love all the help I can get.

The errors I get: 6x Some scripts have compilation errors which may prevent obsolete API usages to get updated. Obsolete API updating will continue automatically after these errors get fixed. and 1x Assets/ThirdPersonCameraScript.cs(23,38): error CS0176: Static member `UnityEngine.Camera.main' cannot be accessed with an instance reference, qualify it with a type name instead 1x Error CS0176 Member 'Camera.main' cannot be accessed with an instance reference; qualify it with a type name instead

This is my script:

using UnityEngine; using System.Collections;

public class ThirdPersonCameraScript : MonoBehaviour { private const float Y_ANGLE_MIN = 0.0f; private const float Y_ANGLE_MAX = 50.0f;

 public Transform lookAt;
 public Transform camTransform;

 private Camera Cam;

 private float distance = 10.0f;
 private float currentX = 0.0f;
 private float currentY = 0.0f;
 private float sensitivityX = 4.0f;
 private float sensivityY = 1.0f;

 private void start()
 {
     camTransform = transform;
     Cam = GetComponent<Camera>().main;

 }

 private void Update()
 {
     currentX += Input.GetAxis("Mouse X");
     currentY += Input.GetAxis("Mouse Y");

     currentY = Mathf.Clamp(currentY, Y_ANGLE_MIN, Y_ANGLE_MAX);
 }


 private void LateUpdate()
 {
     Vector3 dir = new Vector3(0, 0, -distance);
     Quaternion rotation = Quaternion.Euler(currentY, currentX, 0);
     camTransform.position = lookAt.position + rotation * dir;
     camTransform.LookAt(lookAt.position);
 }
 

}