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);
        }
    }
}

Well, this part:

 else if (instance != ("Level_01") || instance != ("Level_02"))
 {
     instance = DestroyObject;
 }

makes no sense, instance is not a string so comparing is a no go, it would appear you have no operator overrides to take in a string thats wrapped in parenthesis for some reason, did you want to compare the active scene? Anyways, that else/if make no sense whatsoever(including the DestoryObject to instance assignment.