click on object then zoom in

I am totally new here. What I want to do is write a #c code to make sure following steps

I have three object in the screen. What I want to do is 1. after click on one of the object, 2. other two disappear, 3. the one I choose leave alone. 4. And I can play around with it(zoom in; roast).

here is the code I have for roast using UnityEngine; using System.Collections;

public class movingbook : MonoBehaviour {

 public float speed = 0.8f;
 public float zoomMax = 1.5f;
 public float zoomMin = 1f;
 public float yMax = 5f;
 public float yMin = 2.5f;
 public float zMax = 1f;
 public float zMin = -7.5f; //various speeds that affect how fast the heart rotates and moves

 Camera camera;

 void Start() //when the game starts
 {
     camera = GameObject.FindGameObjectWithTag("MainCamera").GetComponent<Camera>(); //calls onh the main camera to be used later
 }

 void FixedUpdate() //calls every fixed number of frames (not specified here)
 {
     float inputX = Input.GetAxis("Mouse X") * speed; //calls the mouse moving left and right
     float inputY = Input.GetAxis("Mouse Y") * speed; //calls the mouse moving up and down
     float zoom = Input.GetAxis("Mouse ScrollWheel"); //calls the mouse scroll wheel


     if (Input.GetMouseButton(0)) //if left click is pushed. 
     {
         transform.Translate(0, inputY, -inputX, Space.World);
         Vector3 pos = transform.position;
         pos.y = Mathf.Clamp(pos.y, yMin, yMax);
         pos.z = Mathf.Clamp(pos.z, zMin, zMax);
         transform.position = pos;
     }

     if (Input.GetMouseButton(1))
     {
         transform.Rotate(0, -inputX, -inputY, Space.World); //rotate the heart according to how the user moves his mouse with the mouse button pressed.
     }

     if (Input.GetAxis("Mouse ScrollWheel") != 0) //if the scroll wheen is cycled up or down
     {
         float camFOV = camera.fieldOfView;
         camFOV -= zoom;
         camFOV = Mathf.Clamp(camFOV, zoomMax, zoomMin);
         camera.fieldOfView = camFOV;
     }
 }

} What I need to add for select and zoom in?