Keyboard / Mouse control for FPS

Hi! I m brand new to Unity. I have an issue regarding first person camera control.

I have found a useful scrip online from defjr.com which goes like this.

 using UnityEngine;
 using System.Collections;
  
 public class SimpleControls : MonoBehaviour {
     public Transform cameraPivot;
     public CharacterController character;
     private Vector3 initialPosition;
     private Vector3 currentPosition = Vector3.zero;
     private float speed = 2.5f;
     private Vector2 rotationSpeed = new Vector2 (75, 50);
     private float currentRotation = 75f;
     private float rotationLimitX = 150f;
     private bool changingView = false;
  
     void Update ()
     {
         if (Mathf.Abs (Input.GetAxis ("Horizontal")) < 0.1f)
             currentRotation = rotationSpeed.x;
         else
             currentRotation += 1f;
         if (currentRotation > rotationLimitX) currentRotation = rotationLimitX;
         character.SimpleMove(character.transform.forward * speed * Input.GetAxis("Vertical"));
         transform.Rotate(0, currentRotation * Time.deltaTime * Input.GetAxis ("Horizontal"), 0, Space.World);
         if (Input.GetMouseButtonDown(0)) {
             changingView = true;
             initialPosition = Input.mousePosition;
         }
         if (Input.GetMouseButtonUp(0))
             changingView = false;
         if (changingView) {
             currentPosition.x = Mathf.Clamp ((Input.mousePosition.x - initialPosition.x) / 100, -3, 3);
             currentPosition.y = Mathf.Clamp ((Input.mousePosition.y - initialPosition.y) / 100, -2, 2);
             currentPosition.x *= rotationSpeed.x;
             currentPosition.y *= rotationSpeed.y;
             currentPosition *= Time.deltaTime;
             transform.Rotate (0, currentPosition.x, 0, Space.World);
             cameraPivot.Rotate (-currentPosition.y, 0, 0);
         }
         if (Mathf.Abs( Input.GetAxis("Vertical")) > 0.25f )
             cameraPivot.rotation = Quaternion.Slerp (cameraPivot.rotation, transform.rotation, Time.deltaTime);
     }
 }

This is close to what I want. But m looking for something like on this page http://demo.memcosoft.com/en/repository/9-Shams-ArRiyadh-[Made-by-iXiBiT].html Hope its alright to paste link.

Any help on getting first person to behave like the link above.

Thanks and Regards, Vinay