[2D] Applying CeilingCheck and GroundCheck

Hey guys. I keep encounting null reference error using sample coding. I notice that my sprite didn't have ceilingcheck and groundcheck as the image shown.

I'm wondering how to apply both check. I think that it is the problem of my error. Can anyone help me? or can give the tutorial on moving a sprite?

I put along the coding i use in moving the character from sample assets (beta) in unity store. ty.

PlatformerCharacter2D

 using UnityEngine;
 
 public class PlatformerCharacter2D : MonoBehaviour 
 {
     bool facingRight = true;                            // For determining which way the player is currently facing.
 
     [SerializeField] float maxSpeed = 10f;                // The fastest the player can travel in the x axis.
     [SerializeField] float jumpForce = 400f;            // Amount of force added when the player jumps.    
 
     [Range(0, 1)]
     [SerializeField] float crouchSpeed = .36f;            // Amount of maxSpeed applied to crouching movement. 1 = 100%
     
     [SerializeField] bool airControl = false;            // Whether or not a player can steer while jumping;
     [SerializeField] LayerMask whatIsGround;            // A mask determining what is ground to the character
     
     Transform groundCheck;                                // A position marking where to check if the player is grounded.
     float groundedRadius = .2f;                            // Radius of the overlap circle to determine if grounded
     bool grounded = false;                                // Whether or not the player is grounded.
     Transform ceilingCheck;                                // A position marking where to check for ceilings
     float ceilingRadius = .01f;                            // Radius of the overlap circle to determine if the player can stand up
     Animator anim;                                        // Reference to the player's animator component.
 
 
     void Awake()
     {
         // Setting up references.
         groundCheck = transform.Find("GroundCheck");
         ceilingCheck = transform.Find("CeilingCheck");
         anim = GetComponent<Animator>();
     }
 
 
     void FixedUpdate()
     {
         // The player is grounded if a circlecast to the groundcheck position hits anything designated as ground
         grounded = Physics2D.OverlapCircle(groundCheck.position, groundedRadius, whatIsGround);
         anim.SetBool("Ground", grounded);
 
         // Set the vertical animation
         anim.SetFloat("vSpeed", rigidbody2D.velocity.y);
     }
 
 
     public void Move(float move, bool crouch, bool jump)
     {
 
 
         // If crouching, check to see if the character can stand up
         if(!crouch && anim.GetBool("Crouch"))
         {
             // If the character has a ceiling preventing them from standing up, keep them crouching
             if( Physics2D.OverlapCircle(ceilingCheck.position, ceilingRadius, whatIsGround))
                 crouch = true;
         }
 
         // Set whether or not the character is crouching in the animator
         anim.SetBool("Crouch", crouch);
 
         //only control the player if grounded or airControl is turned on
         if(grounded || airControl)
         {
             // Reduce the speed if crouching by the crouchSpeed multiplier
             move = (crouch ? move * crouchSpeed : move);
 
             // The Speed animator parameter is set to the absolute value of the horizontal input.
             anim.SetFloat("Speed", Mathf.Abs(move));
 
             // Move the character
             rigidbody2D.velocity = new Vector2(move * maxSpeed, rigidbody2D.velocity.y);
             
             // If the input is moving the player right and the player is facing left...
             if(move > 0 && !facingRight)
                 // ... flip the player.
                 Flip();
             // Otherwise if the input is moving the player left and the player is facing right...
             else if(move < 0 && facingRight)
                 // ... flip the player.
                 Flip();
         }
 
         // If the player should jump...
         if (grounded && jump) {
             // Add a vertical force to the player.
             anim.SetBool("Ground", false);
             rigidbody2D.AddForce(new Vector2(0f, jumpForce));
         }
     }
 
     
     void Flip ()
     {
         // Switch the way the player is labelled as facing.
         facingRight = !facingRight;
         
         // Multiply the player's x local scale by -1.
         Vector3 theScale = transform.localScale;
         theScale.x *= -1;
         transform.localScale = theScale;
     }
 }

and

Platformer2DUserControl

 using UnityEngine;
 
 [RequireComponent(typeof(PlatformerCharacter2D))]
 public class Platformer2DUserControl : MonoBehaviour 
 {
     private PlatformerCharacter2D character;
     private bool jump;
 
 
     void Awake()
     {
         character = GetComponent<PlatformerCharacter2D>();
     }
 
     void Update ()
     {
         // Read the jump input in Update so button presses aren't missed.
 #if CROSS_PLATFORM_INPUT
         if (CrossPlatformInput.GetButtonDown("Jump")) jump = true;
 #else
         if (Input.GetButtonDown("Jump")) jump = true;
 #endif
 
     }
 
     void FixedUpdate()
     {
         // Read the inputs.
         bool crouch = Input.GetKey(KeyCode.LeftControl);
         #if CROSS_PLATFORM_INPUT
         float h = CrossPlatformInput.GetAxis("Horizontal");
         #else
         float h = Input.GetAxis("Horizontal");
         #endif
 
         // Pass all parameters to the character control script.
         character.Move( h, crouch , jump );
 
         // Reset the jump input once it has been used.
         jump = false;
     }
 }

PLEASE.PLEASE.PLEASE. I'm newbie in C# and have basic skill in Unity. I really appreciate your help. Thanks guys