Someone help me please! I am really tired

Hello hero, so I am beginner, and basically what i want to do is, Whenever I switch scenes while playing, I have this button Esc. as pauses the game and loads u to a screen where it has paused.... the problem is I can't stop the music already playing at the beginning of the start, where it keep on playing and when i press Esc. i get to the paused scene, but the old music is still playing with the other music which is really annoying, Here is the code below.

The errors i get are 2, first is error CS0019: Operator !=' cannot be applied to operands of type MusicPlayer' and string' second is error CS0428: Cannot convert method group DestroyObject' to non-delegate type `MusicPlayer'. Consider using parentheses to invoke the method

 using UnityEngine;
 using System.Collections;
 
 public class MusicPlayer : MonoBehaviour
 {
     static MusicPlayer instance = null;
 
     void Awake ()
     {
         Debug.Log("Music player Awake" + GetInstanceID());
         if (instance != null)
         {
             Destroy (gameObject);
             Debug.Log("Duplicate Music player self-destructing!");
         }
         else if (instance != ("Level_01") || instance != ("Level_02"))
         {
             instance = DestroyObject;
         }
         else
         {
             instance = this;
             GameObject.DontDestroyOnLoad(gameObject);
         }
     }
 }