Photon NickNames

Question

I was trying to add Nicknames to my game. Everything is okay, but when im entering playmode, the player isn't moving, and in Console Unity sends me this message:

object reference not set to an instance of an object

HERE'S SCRIPT FOR PLAYER:

using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using Photon.Pun;
using UnityEngine.UI;

public class Player : MonoBehaviourPun
{
    private float X, Y;
    public float speed;
    private bool isf;
    PhotonView view;
    private Joystick joystick;
    private Rigidbody2D rb;
    public Text textName;

    // Start is called before the first frame update
    void Start()
    {
        textName.text = view.Owner.NickName;
        rb = GetComponent<Rigidbody2D>();
        view = GetComponent<PhotonView>();
        joystick = GameObject.FindGameObjectWithTag("Joystick").GetComponent<Joystick>();

    }

    // Update is called once per frame
    void Update()
    {
        X = joystick.Horizontal * speed;
        Y = joystick.Vertical * speed;


        if (view.IsMine)
        {
            rb.velocity = new Vector2(X, Y);

            Vector2 moveInput = new Vector2(Input.GetAxisRaw("Horizontal"), Input.GetAxisRaw("Vertical"));
            Vector2 moveAmount = moveInput.normalized * speed * Time.deltaTime;
            transform.position += (Vector3)moveAmount;
        }
    }
}

HERE'S SCRIPT FOR MENU MANAGER:

using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using UnityEngine.UI;
using Photon.Pun;
using Photon.Realtime;


public class MenuManager : MonoBehaviourPunCallbacks
{
    public InputField createInput;
    public InputField joinInput;
    public InputField inputName;

    public void CreateRoom()
    {
        RoomOptions roomOptions = new RoomOptions();
        roomOptions.MaxPlayers = 4;
        PhotonNetwork.CreateRoom(createInput.text, roomOptions);
    }

    public void JoinRoom()
    {
        PhotonNetwork.JoinRoom(joinInput.text);
    }

    public override void OnJoinedRoom()
    {
        PhotonNetwork.LoadLevel("Game");
    }

    public void SaveName()
    {
        PlayerPrefs.SetString("name", inputName.text);
        PhotonNetwork.NickName = inputName.text;
    }

    void Start()
    {
        inputName.text = PlayerPrefs.GetString("name");
        PhotonNetwork.NickName = inputName.text;
    }
}

I was expecting to see nicknames in my game. As a result, my player is not moving, and there is an error in the console.