I'm trying to create a life system for my player but my codes not working, anyone got any ideas?

I'm really new to coding so i got this from a tutorial but its just not liking me.

public class LifeManager : MonoBehaviour {

 public int startingLives;
 private int lifeCounter;

 private Text theText;

 public GameObject gameOver;
 public PlayerControl player;

 // Use this for initialization
 void Start () {
     theText = GetComponent<Text> ();

     lifeCounter = startingLives;

     player = FindObjectOfType<Player>();
 }
 
 // Update is called once per frame
 void Update () {

     if (lifeCounter < 0) {

         gameOver.SetActive (true);
         player.gameObject.SetActive (false);
     }

     theText.text = "x " + lifeCounter;
 }


     public void GiveLife()
 {
     lifeCounter++;
 }

     public void TakeLife()
 {
     lifeCounter--;
 }

}