error CS0019: Operator `==' cannot be applied to operands of type `UnityEngine.GameObject' and `string'

Hello, I am running into a wall here and I would like help. I have this empty parent game object that holds many children cube game objects that has colliders and another empty game object that has a collider of its own.

I want each of the respective children game object have their things called in the OnTriggerEnter because each children game object is supposed to cause an event in the game that I want it happen such as a dialogue box appearing.

However, it says I can't have strings to compare if two gameobjects have collided with eachother and I would like people's help if they could give me advise. Thanks in advance, I will continue to keep fiddling with this.

Here is the code I'm trying to work with:

 public class Wave0TutorialEventManager : MonoBehaviour 
 {
 
     public string collisionTagPlane = "PlayerPlane"; //The Player Plane Game Object
     private GameObject cameraGUI;  //The camera that will show all the text Boxes
     private GameObject wave0TutorialEvent1;
     private GameObject wave0TutorialEvent2;
 
     void Start()
     {
         cameraGUI = GameObject.FindGameObjectWithTag ("TextBoxCamera");
         wave0TutorialEvent1 = GameObject.Find ("Wave0TutorialEvent1");
         wave0TutorialEvent2 = GameObject.Find ("Wave0TutorialEvent2");
     }
 
     void OnTriggerEnter(Collider col)
     {
         if(wave0TutorialEvent1 == collisionTagPlane)
         {
             cameraGUI.SendMessage ("Wave0TutorialEvent1", true);
             Debug.Log ("Player Area has reached this point");
         }
 
         if(wave0TutorialEvent2 == collisionTagPlane)
         {
             cameraGUI.SendMessage ("Wave0TutorialEvent2", true);
             Debug.Log ("Player Area has reached second point");
         }    
     }
 }