Stopping score count after player is destroyed?

I'm trying to make my first game but I've been stuck on this problem for a while now. I can't seem to figure out how to check if the player is dead and stop score count. Also I want to know how to store that score.

My game is simple. You have to dodge a lot of spheres for as long as you can and get the high score.

But when my player collides with one of the spheres, the game still carries on. I have a "Move Forward" script for the enemy spheres that move at a certain speed, and a "Destroy Out of Bounds" script for when the spheres pass the player, they get destroyed off-screen and add 5 points to the score. I do have the "Game Manager" script that spawns all the spheres and to show the current score. (I may need to re-route some coding right?)

Here's what's in my Game Manager script. I need to know how to really check if the player is dead when something happens.

using TMPro;
using UnityEngine;

public class GameManager : MonoBehaviour
{
    public GameObject[] EnemyPrefabs;
    private float spawnRangeX = 17;
    private float spawnPosZ = 35;
    private float StartDelay = 2.2f;
    private float SpawnInterval = 0.1f;
    public bool PlayerAlive;
    public TextMeshProUGUI scoreText;
    private int score;
    public TextMeshProUGUI gameOverText;
    // Start is called before the first frame update
    void Start()
    {
        score = 0;
        UpdateScore(0);

        InvokeRepeating("SpawnRandomEnemy", StartDelay, SpawnInterval);

    }

    // Update is called once per frame
    void Update()
    {
        PlayerAlive = true;
    }

    public void UpdateScore(int scoreToAdd)
    {
        score += scoreToAdd;
        scoreText.text = "Score: " + score;
    }


    void SpawnRandomEnemy()
    {
        int enemyIndex = Random.Range(0, EnemyPrefabs.Length);
        Vector3 spawnPos = new Vector3(Random.Range(-spawnRangeX, spawnRangeX), 0, spawnPosZ);
        Instantiate(EnemyPrefabs[enemyIndex], spawnPos, EnemyPrefabs[enemyIndex].transform.rotation);
    }
}

In the "player" script, I have a "private void OnTriggerEnter(Collider other)" to have the player be destroyed and activate the "game over" text. I also put a "PlayerAlive = false" there because I'm still trying to figure this out.

The problem is with this part of your code:

// Update is called once per frame
void Update()
{
    PlayerAlive = true;
}

This doesn't make sense to me, because as long as a GameManager instance exists, every frame, the value of PlayerAlive will be updated to true, regardless of if you set it to false somewhere else.

You should move that line of code inside your Start function to initialize PlayerAlive to true.

Now since a specific trigger collider in the Player class will set it to false, what you need to do is add a simple check to UpdateScore like so:

public void UpdateScore(int scoreToAdd)
{
    // if player is dead, then do nothing
    if(!PlayerAlive) return;

    score += scoreToAdd;
    scoreText.text = "Score: " + score;
}

Hope this solves your issue!