NullReferenceException: Changing text... keeps throwin:Object reference not set to an instance of an object

using UnityEngine;
using System.Collections;
using UnityEngine.UI;

public class Ctrl : MonoBehaviour {
public Text myText;

// Use this for initialization
void Start () {
	myText = GetComponent<Text>();
	myText.text = "myText...";
}

// Update is called once per frame
void Update () {

}

}

Im actually following the Tutorial from Unity lessons, but it don’t like me… I’m using
free version of 5.0.

What I am trying to do is get the Text component on the canvas and simply change the text on start dynamically as want to update it from a button event.

before void Start add, GameObject myText;
not really sure what"myText…" is but after you did this it should work