How do I make a score system?

Questions & Answers
1

I do the tutorial score manager but when I do everything it does not work. PLEASE HELP.

Here’s the Enemy Health -

  using System.Collections;
  using UnityEngine;
  
  public class EnemyHealthManager : MonoBehaviour {
  
      public int MaxHealth;
      public int CurrentHealth;
      public int scoreValue = 10;
  
      // Use this for initialization
      void Start()
      {
          CurrentHealth = MaxHealth;
      }
  
      // Update is called once per frame
      void Update()
      {
          if (CurrentHealth <= 0)
          {
              Destroy(gameObject);
          }
      }
  
      public void HurtEnemy(int damageToGive)
      {
          CurrentHealth -= damageToGive;
      }
  
      public void SetMaxHealth()
      {
          CurrentHealth = MaxHealth;
      }
  
      public void Scoring()
      {
          ScoreManager.score += scoreValue;
      }
  }

Here’s the ScoreManger -

using UnityEngine; 
using UnityEngine.UI; 
using System.Collections;
 
  public class ScoreManager : MonoBehaviour
  {
      public static int score;
  
  
      Text text;
  
      void Awake()
      {
          text = GetComponent<Text>();
          score = 0;
      }
  
  
      void Update()
      {
          text.text = "Score: " + score;
      }
  }
2

@username

Updating score in Update() will create a new memory block each time when you change score , so its not good approach to update scoring.
Make a unity event and listen in your ScoreManager class as in the script.

using UnityEngine.UI;

public class ScoreManager : MonoBehaviour {

    Text _text;
    [NotNull] public static UnityEvent ScoreUpdateEvent;
    public static int Score;

    private void Start()
    {
        _text = GetComponent<Text>();
        ScoreUpdateEvent.AddListener(delegate
        {
            _text.text = "Score: " +Score;

        });
    }
}

Now your ScoreManager class is listening ScoreUpdateEvent you just need to invoke the event whenever you change the score.

  public void Scoring()
    {
        ScoreManager.Score += scoreValue;
        ScoreManager.ScoreUpdateEvent.Invoke();           // invoke here
    }