How to make object reappear at different heights and fly across screen?,How do you make projectiles reappear at different heights?

I have this 3D game about a ball bouncing up and down, and it’s supposed to avoid sharp objects. I’m a Unity noob and would like to know if it’s possible to repeat:

-make multiple objects at different heights

-have them fly across the screen, and

-have them reappear at different heights

I know it sounds like hell but I can’t find anything on YouTube so im stuck with this post.

Just so happens I needed a similar code. Here,

 using System.Collections;
    using System.Collections.Generic;
    using UnityEngine;
    public class SpawnerScript : MonoBehaviour
        public GameObject Ball;
        float delay;
        // Start is called before the first frame update
        void Start()
            delay = Random.Range(1f, 3f);
        IEnumerator Spawner(float d)
            yield return new WaitForSeconds(d);
            InstantiateBall, transform.position, transform.rotation);
            delay = Random.Range(0.001f, 0.1f);