an object reference is required to access non-static member

I know this is a frequent issue, but here's the code:

 using UnityEngine;
 using System.Collections;
 
 public class CameraMovement : MonoBehaviour {
     int CameraMovementSpeed = 2;
     // Use this for initialization
     void Start () {
     
     }
 
     // Update is called once per frame
     void Update () {
         Transform.Translate (0, 0, CameraMovementSpeed);
     }
 }

I'm new to Unity and C#, in fact my only experience is in basic C++ programming. I have two questions:

• Why isn't this working? I'm trying to mimic this javascript version: http://youtu.be/K81JJdA2lnk?t=10m34s

• Why does it all have to be in class brackets? Can't it look like this instead? (Here it even complains about the "int CameraMovementSpeed = 2;")

  using UnityEngine; using System.Collections;

     int CameraMovementSpeed = 2;
   
       // Update is called once per frame
  
          void Update () {
           Transform.Translate (0,0,CameraMovementSpeed);
       }