Scoring points problem

Hello everyone,
I am new in Unity and I need your help. I am doing game almost same as on Image but I have got there 4 pick up objects with different shapes.

I dont know how to count score,under every side of square I have placed empty game object with script attached.

 void OnTriggerEnter2D(Collider2D other)
    {

        if (other.gameObject.CompareTag("Triangel"))
        {
            Destroy(other.gameObject);
            clipAudio.Play();
            count = count + 1;


        }

    }

But when I picked up different object score has restarted.
Here is my ScoreController which doesnt work.
I have no idea what to do next. Please help me I will appreciate it.

public Text countText;
public int count;
public int Count1;
public int Count2;
public int Count3;
public int Count4;

private void Start()
{
    
   

    Count1= GameObject.Find("Triangels").GetComponent<TriangelsPickUp>().count1;
    Count2 = GameObject.Find("Squares").GetComponent<SquaresPickUp>().count2;
    Count3 = GameObject.Find("Circles").GetComponent<CirclesPickUp>().count3;
    Count4 = GameObject.Find("Diamonts").GetComponent<DiamontsPickUp>().count4;
    SetCountText();
    count = 0;
    

}

private void Update()
{
    count = Count1+Count2+Count3+Count4;
    SetCountText();       
}
void SetCountText()
{
  countText.text = "Score: " + count.ToString();
}

I’d like to help as I had the same issue a while back. But my game is 3D not 2D and I know nothing about 2d. My score is text on the HUD Canvas with a "score manager "script attached to it. this is the script I use on the scoretext

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

public class ScoreManager : MonoBehaviour
{
	public static int score = 00; 

	void Awake ()
	{
	
		text = GetComponent <Text> ();
		
	}
	

	void Update ()
	{
		
	
		text.text = "Score: " + score;

}
}

and to add to the score on another gameObject

void OnTriggerEnter (Collider other) {

	if(other.tag == "Grenade")
			
		ScoreManager.score+=100;
}

}