I can not detect collisions !!! Pls Help !!! I have put colliders on all objects and a Rigidbody2D on the one with the script. I have also put the object to dynamic, not kinematic. Also, I am new to unity.

using UnityEngine;

public class BallCollision : MonoBehaviour
     private void OnTriggerEnter2D(Collider2D collider)
           Debug.Log("pls work");

Do your colliders have isTrigger property? OnTriggerEnter2D callback is called only when contact with trigger collider. Read more about it in unity docs

I have a “}” at the end but I forgot to put it here.