Can someone help me with getting a script that'll recognize when I have a certain amount of rocks in my inventory?

Here's the link to the post where "Tanoshimi" gave me an incomplete script.

Or maybe a simpler way would be to make a script where it goes like, when all objects tagged "Stones" are all gone, the collider activates? That seems like it would be easier.

@tanoshimi gave you all that you really needed.

Remember this is a site for people with Unity related questions. It is not a site to $$anonymous$$ch people how to program (there are more than enough of those out there).

tanoshimi is assu$$anonymous$$g that you have some basic knowledge of creating classes in C#. So as he wrote in his reply the snippet

needs to be contained in a proper C# class definition, in which case "playerInventory" becomes a slot exposed in the inspector panel onto which you can drag and drop the player inventory.

What this means is you need to supply this

 using UnityEngine;
 using System.Collections;
 using System.Collections.Generic; // this is needed for Lists
 
 public class $$anonymous$$yClassName : $$anonymous$$onoBehaviour
 {
     // SNIPPET CODE HERE
 }

where // SNIPPET CODE HERE is the snippet supplied by tanoshimi. So basically the resulting class would look something like this

 using UnityEngine;
 using System.Collections;
 using System.Collections.Generic; // this is needed for Lists
 
 public class $$anonymous$$yClassName : $$anonymous$$onoBehaviour
 {
     [Tooltip("Drag your player's inventory into this slot")]
     [SerializeField]
     private Inventory playerInventory; 
 
     [Tooltip("Set this to the ID of the stone in your inventory system")]
     [SerializeField]
     private int stoneID;
 
     // Something entered the spot...
     void OnTriggerEnter(Collider other)
     {
         // .. was it the player?
         if (other.CompareTag("Player") )
         {
             // If so, rummage through their inventory
             List<Item> items = playerInventory.getItemList();
 
             // and count up how many stones they have
             int numStones = 0;
             for(int i=0; i<items.Count; i++)
             {
                 if (items[i].itemID == stoneID)
                     numStones++;
             }
             // Do they have enough?
             if(numStones >= 60)
             {
                 SOSAnimation.Play();
             }
         }
     }
 }

But as tanoshimi stated you do need to set up everything in the inspector properly.