How to Instantiate Object within it's parent borders

I am trying to make a game where you climb up on platforms to get to the top, but the platforms need to be generated randomly as the game starts. The problem is that the platforms start from the bottom of the project, but then spread either left or right outside of the camera boundaries. I created a parent GameObject(Collider) to keep the platforms wit$$anonymous$$n it's borders, but I am kinda new to the game development with Unity so I gave up trying to make it work.

Here's the code below:

P.S The float levelWidth decides how far tiles should be one from another by the x axis, but as I write a number like "10" the tiles get spread. T$$anonymous$$s was my first idea but it didn't work out. minY, maxY decides the distance between tiles by the y axis.

 using System.Collections;
 using System.Collections.Generic;
 using UnityEngine;
 
 public class LevelGenerator : MonoBehaviour
 {
     [SerializeField] GameObject platformPrefab;
     [SerializeField] GameObject Collider;
 
     [SerializeField] int numberOfPlatfoms;
     [SerializeField] float levelWidth;
     [SerializeField] float minY;
     [SerializeField] float maxY;
 
     // Start is called before the first frame update
     void Start()
     {
         Vector3 spawnPosition = new Vector3();
 
         for (int i = 0; i < numberOfPlatfoms; i++)
         {
             spawnPosition.y += Random.Range(minY, maxY);
             spawnPosition.x += Random.Range(-levelWidth, levelWidth);
             Instantiate(platformPrefab, spawnPosition, Quaternion.identity);
         }
     }
 
     // Update is called once per frame
     void Update()
     {
 
     }
 }