Iterate through dialogue array and display in game

What end product am I trying to archive:

I am making a Walking Sim in which different characters talk whenever a certain event is triggered.

(Sometimes when you walk past a certain place on the map, sometimes when you pick or interact with an item and sometimes after a certain time).

The Dialogue is played in a set order.

There is, however, one option to skip a part of the story.

What I have so far:

A Dialogue Script:

  [System.Serializable] public class Dialogue 
 {

 [SerializeField]
 private string nameOfSpeaker; //Adding the name of the current speaker in the Unity Inspector

 [SerializeField]
 [TextArea(3,10)]
 private string sentence; //Adding the displayed sentence the speaker says in the Unity Inspector
 }

A Dialogue Manager:

  public class DialogueManager : MonoBehaviour
 {
   private Dialogue dialogue; 

  //Adding a variable from type Dialogue to be able to access it's variables (See "Dialogue"-Script for 
  reference)

 List<Dialogue[]> chapters = new List<Dialogue[]>(); //Making a List of Dialogue Arrays

 /*Since the player will be able to skip a part of the dialogue 
  * we added divided the story into chapters and
  * made them seperate arrays. ChapterOne has to be played, 
  * ChapterTwo is skippable and ChapterThree is the ending, wheather or not
  * the second chapter is skipped*/
 [SerializeField] 
 private Dialogue[] chapterOne;
 [SerializeField] 
 private Dialogue[] chapterTwo;
 [SerializeField] 
 private Dialogue[] chapterThree;

 [SerializeField]
 private TMP_Text text; //drag and drop the TMPText that should display the current dialogue sentence


 private void OnEnable() //subscribing to the Event that triggers the current Dialogue[i] to be played
 {
     Message<ContinueDialogueEvent>.Add(OnContinueDialogue);
 }
 
 private void OnDisable()//unsubscribing to the Event that triggers the current Dialogue[i] to be played
 {
     Message<ContinueDialogueEvent>.Remove(OnContinueDialogue);
 }

 private void Start() //Adding the Chapters to the List 
 {
     chapters.Add(chapterOne);
     chapters.Add(chapterTwo);
     chapters.Add(chapterThree);
 }

 public void StartDialogue (Dialogue dialogue) 
 {
     Debug.Log(message: "Started a conversation");

 }

 private void OnContinueDialogue(ContinueDialogueEvent ctx) //See "DialogueTrigger"-Script for reference
 {
     Debug.Log("Continue Dialogue in Chapter " + ctx.Chapter);
 }
 }

A DialogueTrigger (not Sure if this is important):

 public class DialogueTrigger : MonoBehaviour
 {
     [SerializeField] private bool isTriggered; //Checking weather or not the Dialogue has been triggered
     [SerializeField] private bool wasExecuted; //Checking weather or not it has already been executed
     [SerializeField] private int chapter; //Chapter 1-3

     private void OnTriggerEnter(Collider other) //Triggering Dialogue through walking through an invisible collider
     {
         if (!wasExecuted)
         {
             if (isTriggered)
             {
                 NextDialogue();
             }
         }
     }

     public void NextDialogue()
     {
         if (!wasExecuted)
         {
             Message.Raise(new ContinueDialogueEvent(chapter));
         }
         wasExecuted = true;
     }
 }

What I need help with:

I wanted to add a Variable (index) that is raised by one everytime a Dialgoue is triggered and then use this Variable to display the next Dialogue (nameOfSpeaker and Sentence) in the Array. Lets assume we just want to do all that with ChapterOne[].

Questions:

• How do I display the Dialogue (the nameOfSpeaker and Sentence) in Unity (I am using TMP)?

• How do I write this Method best?

I have been watching a lot of Dialogue Tutorials yet none seems to help me with my exact case.

I think the solution to this problem is quite easy compared to what I have already done, but I have been staring at this for too long and do not know how to continue.

Info: I am neither well experienced in Unity nor coding.