Moving between scenes like an adventure game

Hey, I am new to programming but have been working on a project for a few months now. I am making a 2D game that is supposed to let you move between scenes like in an adventure game. I was using playprefs to store spawn locations for the next scene, but that has recently started becoming very unpredictable.

I have read in many places that I better way to handle this would be to create a singleton object to manage where the character spawns. Could anyone give me any resources that could guide me in how to go about this? I am still very new to all this still and am having a lot of trouble with trying to figure this out.

The script I have bee using is this one, and is attached to trigger objects that are places at both ends of my scene:

 using UnityEngine;
 using System.Collections;
 using UnityEngine.SceneManagement;
 
 public class DoorTrigger2 : MonoBehaviour {
 
     public GameObject MyPlayer;
     public int levelInt;
 
     public float spawnX;
     public float spawnY;
 
 
 
     void OnTriggerEnter2D(Collider2D target)
     {
         if (target.gameObject.tag == "player")
 
             PlayerPrefs.SetFloat ("spawnX", spawnX);
             PlayerPrefs.SetFloat ("spawnY", spawnY);
 
             SceneManager.LoadScene ("level" + levelInt);
 
         
 
     }
 
     void OnLevelWasLoaded ()
     {
         
 
         MyPlayer.transform.position = new Vector3 (PlayerPrefs.GetFloat ("spawnX"), PlayerPrefs.GetFloat ("spawnY"), 0);

//I recently tried to debug to see where the player was trying to spawn, found spawn points to often be far from where I was intending

         Vector3 spawnPt = new Vector3 (PlayerPrefs.GetFloat ("spawnX"), PlayerPrefs.GetFloat ("spawnY"), 0);
         Debug.DrawRay (MyPlayer.transform.position, spawnPt, Color.blue, 1.0f);
         Debug.Log ("Line here");
     }
 
 
 }