Prefab is not shown in unity

When I ADD:

public GameObject playerPrefab;

According to burgzergarcade.com
playerPrefab should be their in the character generator script to main camera.
When I try to do it along with him it is not displayed.

The CharacterGenerator script is:

using UnityEngine;
using System.Collections;
using System;						//used for the enum class
public class CharacterGenerator : MonoBehaviour {
	# region PRIVATES
	private PlayerCharacter _toon;
	private const int Starting_Points = 350;
	private const int MIN_STARTING_ATTRIBUTE_VALUE = 10;
	private const int STRARTING_VALUE = 50;
	private int pointsleft;
	
	private const int OFFSET = 5;
	private const int LINE_HEIGHT = 20;
	
	private const int STAT_LABEL_WIDTH = 110;
	private const int BASEVALUE_LABEL_WIDTH  = 30;
	
	private const int BUTTON_WIDTH = 20;
	private const int BUTTON_HEIGHT = 20;

	private  int STAT_STARTING_POS = 40;
	
	public GUIStyle mystyle;
	
	public GameObject playerPrefab;
#endregion
	void Start()
	{
	Instantiate(player_Prefab, Vector3.zero, Quaternion.identity);
		_toon = new PlayerCharacter();	
		_toon.Awake();
		
		pointsleft = Starting_Points;
		
		for(int cnt = 0; cnt < Enum.GetValues(typeof(AttributeName)).Length; cnt++){
		_toon.GetPrimaryAttribute(cnt).BaseValue = STRARTING_VALUE;
		pointsleft -= (STRARTING_VALUE - MIN_STARTING_ATTRIBUTE_VALUE);
		}
	
	}
	void Update(){
	_toon.StatUpdate();
		
	}
	void OnGUI(){
	DisplayName();
	DisplayPointsleft();	
	DisplayAttribute();	
	DisplayVitals();
	DispalySkills();
	}
	
	private void DisplayName(){
	GUI.Label(new Rect(10, 10, 50, 25), "Name:");
		_toon.Name = GUI.TextField(new Rect(65, 10, 100, 25), _toon.Name);	
	}
	private void DisplayAttribute(){
		#region Display
		for(int cnt = 0; cnt < Enum.GetValues(typeof(AttributeName)).Length; cnt++){
		GUI.Label(new Rect(OFFSET, 									//x	
				STAT_STARTING_POS +(cnt* LINE_HEIGHT), 				//y
				STAT_LABEL_WIDTH,									//width 
				LINE_HEIGHT),										//height
				((AttributeName)cnt).ToString(), mystyle );	
		GUI.Label(new Rect(STAT_LABEL_WIDTH + OFFSET, 				//x
				STAT_STARTING_POS +(cnt* LINE_HEIGHT), 				//y
				BASEVALUE_LABEL_WIDTH, 								//width
				LINE_HEIGHT), 										//height
				_toon.GetPrimaryAttribute(cnt).AddjustedBaseValue.ToString(), mystyle);
		#endregion
			#region Button
			if(GUI.Button(new Rect(OFFSET + STAT_LABEL_WIDTH + BASEVALUE_LABEL_WIDTH, 	//x
				STAT_STARTING_POS +(cnt* BUTTON_HEIGHT),								//y
				BUTTON_WIDTH, 														//width
				BUTTON_HEIGHT), 													//height						
				"-", mystyle)){														
				
				if(_toon.GetPrimaryAttribute(cnt).BaseValue > MIN_STARTING_ATTRIBUTE_VALUE) {
					_toon.GetPrimaryAttribute(cnt).BaseValue--;
					pointsleft++;
			}
			}
		
			if(GUI.Button(new Rect(OFFSET + STAT_LABEL_WIDTH + BASEVALUE_LABEL_WIDTH + BUTTON_WIDTH , 		//x
				STAT_STARTING_POS +(cnt* BUTTON_HEIGHT),													//y	
				BUTTON_WIDTH, 																				//width
				BUTTON_HEIGHT), 
				"+", mystyle)){																		//height
				
				if(pointsleft > 0) {
					_toon.GetPrimaryAttribute(cnt).BaseValue++;
					pointsleft--;
					
				}
			}
		}
	}
	#endregion
	private void DisplayVitals(){
		for(int cnt = 0; cnt < Enum.GetValues(typeof(VitalName)).Length; cnt++){
		GUI.Label(new Rect(OFFSET, 
				STAT_STARTING_POS + ((cnt + 7) * LINE_HEIGHT), 				//x
				STAT_LABEL_WIDTH, 											//y
				LINE_HEIGHT),												//width			
				((VitalName)cnt).ToString(),mystyle );								//height
		GUI.Label(new Rect(OFFSET + STAT_LABEL_WIDTH, 								//x
				STAT_STARTING_POS + ((cnt + 7) * LINE_HEIGHT), 						//y	
				BASEVALUE_LABEL_WIDTH, 												//width
				LINE_HEIGHT),														//height
				_toon.GetPrimaryAttribute(cnt).AddjustedBaseValue.ToString(), mystyle);
	}
	}
	private void DispalySkills(){
		for(int cnt = 0; cnt < Enum.GetValues(typeof(SkillName)).Length; cnt++){
		GUI.Label(new Rect(OFFSET + STAT_LABEL_WIDTH + BASEVALUE_LABEL_WIDTH + BUTTON_WIDTH * 2 + OFFSET * 2,		//x 
				STAT_STARTING_POS + (cnt * LINE_HEIGHT), 															//y
				STAT_LABEL_WIDTH, 																					//width
				LINE_HEIGHT),																						//height
				((SkillName)cnt).ToString(), mystyle );	
		GUI.Label(new Rect(OFFSET + STAT_LABEL_WIDTH + BASEVALUE_LABEL_WIDTH + BUTTON_WIDTH * 2 + OFFSET * 2 + STAT_LABEL_WIDTH, 	//x
				STAT_STARTING_POS + (cnt  * LINE_HEIGHT), 																			//y
				BASEVALUE_LABEL_WIDTH, 																								//width	
				LINE_HEIGHT), 																										//height	
				_toon.GetPrimaryAttribute(cnt).AddjustedBaseValue.ToString(),mystyle);
	}
	}
	private void DisplayPointsleft(){
	GUI.Label(new Rect(250, 10, 100, 25), "Points Left: " + pointsleft.ToString(),mystyle);

	}
}

can someone help me
I suggest you watch his video

In your start function you are Instantiating a prefab called player_Prefab but the variable you put in is called playerPrefab.

Try renaming your variable to player_Prefab and make sure you assigned a prefab to the variable in the Visual Editor.

Btw. your link just leads to a site with a few articles/videos. Nothing specific to your problem.