Raycast through object

Take a look at LayerMask; it allows you to set objects in a layer that the raycast would then ignore, and effectively "go through" them.

I'd suggest setting the mask as a property or field that's exposed to the Inspector for easier editing. Then your code would look something like:

 using System.Collections; 
 using System.Collections.Generic; 
 using UnityEngine;
 
 public class RayCamera : MonoBehaviour
 {
     public Camera aremac;
     public LayerMask hitMask; // define this in the inspector! remember that checkmarks mean layers to hit
     public float rayRange = float.MaxValue; // making this a public field is optional, but the value is needed for the Raycast call
 
     void Start()
     {
         //Cursor.lockState = CursorLockMode.Locked;
     }
 
     void FixedUpdate()
     {
         RaycastHit hit;
         Ray ray = aremac.ScreenPointToRay(Input.mousePosition);
 
         if (Physics.Raycast(ray, out hit, rayRange, hitMask))
         {
             transform.LookAt(new Vector3(hit.point.x, transform.position.y, hit.point.z)); // Do something with the object that was hit by the raycast.
         }
     }
 }