How do I make a simple Inventory?

Hello, I am very new to unity. I have tried looking at a million videos on this topic. However, the code either goes over my head, or they seem to rush through the code, and implement features that I would not need on this inventory. I am just looking to make a simple inventory that works with a controller. I just want the inventory to hold the items when picked up, and when selected by pressing X on the PS4 controller to either be equipped or used by the player. I have gotten the UI to come up by using the options button on a PS4 controller. I have also made a simple script that I have attached to a game object which displays a pick up message, and destroys the object upon hitting X. here are the scripts for the PickUp, and inventory that I have. any help is much appreciated.

 using System.Collections;
 using System.Collections.Generic;
 using UnityEngine;
 public class PickUp : MonoBehaviour
 {
 
 public GameObject enterText;
 

 public GameObject itemIcon;

 bool pickedUp = false;

 


 // Start is called before the first frame update
 void Start()
 {
     enterText.SetActive(false);
     
     if(pickedUp == false)
     {
         itemIcon.SetActive(false);
     }

    

 }

 // Update is called once per frame
 void Update()
 {
     
 }

 private void OnTriggerStay(Collider player)
 {
     if (player.gameObject.tag == "Player")
     {
         enterText.SetActive(true);
         if (Input.GetButtonDown("Pickup") &&! pickedUp)
         {
            
             pickedUp = true;
             Destroy(gameObject);
             enterText.SetActive(false);
             itemIcon.SetActive(true);

         }
                   

     }
 }
 private void OnTriggerExit(Collider player)
 {
     if (player.gameObject.tag == "Player")
     {
         enterText.SetActive(false);
        
     }
 }
   
  

}

here is the inventory. I have also set up to pause the game when the inventory is displayed on the UI.

  using System.Collections;
     using System.Collections.Generic;
     using UnityEngine;
     
     
     public class Inventory : MonoBehaviour
 
 {
     public GameObject invTab;
     public static bool GameIsPaused = false;
 public GameObject pauseMenuUI;



 // Start is called before the first frame update
 void Start()
 {
     invTab.SetActive(false);
     
 }

 // Update is called once per frame
 void Update()
 {
     if (Input.GetButtonDown("invTab"))
     {
        
         if (GameIsPaused)
         {
             Resume();
         }
         else
         {
             Pause();
         }

        
     }
   
 }
 void Resume()
 {
     invTab.SetActive(false);
     Time.timeScale = 1f;
     GameIsPaused = false;
 }
 void Pause()
 {
     invTab.SetActive(true);
     Time.timeScale = 0f;
     GameIsPaused = true;
 }
 public void LoadMenu()
 {
     Debug.Log("Loading menu..");
 }
 public void QuitGame()
 {
     Debug.Log("Quitting Game....");
 }
 

}