Random Pickup Respawn Manager?(spawn pickups with the tag "PickUp" in random locations)

C#Only How could I set up a system to make my collectables/pickups spawn in random positions?

Also, how could I make a pickup spawn in random locations after the Player collects the pickup with the tag "PickUp"? Would I need to make a new script and call it something like Respawn Manager? If one could lead me in the right direction to understand this as well.

 using UnityEngine;
 using System.Collections;
 
 public class Coin : MonoBehaviour {
 
     public int value;
         public float rotateSpeed;
 
     // Use this for initialization
     void Start () {
     
     }
     
     // Update is called once per frame
     void Update () {
         {
             gameObject.transform.Rotate(Vector3.up * Time.deltaTime * rotateSpeed);
         }
     
     }
 
     void OnTriggerEnter(Collider other)
     {
 
         GameManager.instance.Collect(value, gameObject);        
         AudioSource source = GetComponent<AudioSource>();
         source.Play();
     }
 }