RayCasting.cs

void Update() 
{
    if(Input.GetMouseButtonDown(0)) 
    {
        float hitDist = Mathf.Infinity;
        Ray ray = Camera.main.ScreenPointToRay(Input.MousePosition);
        RaycastHit hit;
    
        if(Physics.RayCast(ray, out hit, hitDist))
        {
            if(hit.collider.CompareTag("Enemy"))
            {
                Destroy(hit.collider.gameobject);
            }
        }
    }
}