Getting UI Text values from a script

I'm new to Unity and using the tutorials. The tutorials however, use the legacy version of Unity's UI system. I have the text positioned in the correct position and it is linked to the public text variable that I have set in the script. When I try to play I get two errors in my start and my update.

NullReferenceException: Object reference not set to an instance of an object PlayerController.Start () (at Assets/Scripts/PlayerController.cs:16)

&

NullReferenceException: Object reference not set to an instance of an object PlayerController.OnTriggerEnter (UnityEngine.Collider other) (at Assets/Scripts/PlayerController.cs:30)

Here is the code for PlayerController:

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

public class PlayerController : MonoBehaviour { public Rigidbody rb; public float speed; public Text countText; private int count; private string stringified; void Start() { rb = GetComponent (); count = 0; countText = GetComponent (); stringified = count.ToString (); countText.text = "Count: " + stringified; }

 void FixedUpdate() {
     float moveHorizontal = Input.GetAxis ("Horizontal");
     float moveVertical = Input.GetAxis ("Vertical");
     Vector3 movement = new Vector3 (moveHorizontal, 0.0f, moveVertical);
     rb.AddForce (movement * speed * Time.deltaTime);
 }
 void OnTriggerEnter(Collider other) {
     if (other.gameObject.tag == "PickUp") {
         other.gameObject.SetActive(false);
         count++;
         stringified = count.ToString ();
         countText.text = "Count: " + stringified;
     }
 }

}