cannot convert from 'UnityEngine.Vector3' to 'UnityEngine.Quaternion'

Here is my code:

can anyone tell why is it showing me this error and how to fix it?

            Vector3 targetPosition=new Vector3(hit.point.x,transform.position.y,hit.point.z);
            Quaternion rotation=Quaternion.LookRotation(targetPosition-transform.position);

It’s because you’re trying to change your position in the last line using Quaternion.Lerp and not Vector3.Lerp.
If you want to rotate your object smoothly you wanna use Quaternion.Lerp(transform.rotation, wantedRotation, rotationSpeed * Time.deltaTime).
For positions on the other hand you wanna use Vector3.Lerp and then the current position, the wanted position and the speed just like in Quaternion.Lerp, but with positions.