How to read text file line by line using C#

Hi,

I am newbie to unity. I have few Questions.
1)
I want to read text file which is in assets folder.
I have tried many solutions from the internet but unable to get it working properly.
I am using following code:

 using UnityEngine;
 using System;
 using System.Collections;
 using System.IO;
 
 
 public class readTextFile : MonoBehaviour {
 
 
     public string filePath ;
     public string result = "";
 
     string str;
     void Start () {
         filePath = System.IO.Path.Combine(Application.streamingAssetsPath, "myFile.txt");
         Debug.Log ("filePath " + filePath);
 
         readFile(); //calling this method to read the data inside the text file
 
     }
     
         IEnumerator readFile() {
 
         Debug.Log("inside readFile");   // this log is not displayed
 
         if (filePath.Contains ("://")) {
             WWW www = new WWW (filePath);
             yield return www;
             result = www.text;
         }  else {
             result = System.IO.File.ReadAllText(filePath);
             Debug.Log ("result string " + result);
             
         }
 
 
     }
 
 }
 

In this code readFile method is not being called. Am I doing something wrong? I have used :

     StreamReader sr = new StreamReader("Assets/myFile.txt");

But it only works on unity Editor and not on mobile platform.

Is there any other way to do this?

2)
I also want to synchronise text(which I am getting from this file) with audio.