Change visibility of an element MVVM wpf

Just yesterday i've started explored mvvm wpf so please, if I do something wrong, don't beat me! I want to change visibility of stackpanel by click on a button. And I have a problem here. My code:

ViewModelBase

    public abstract class ViewModelBase : INotifyPropertyChanged
        {
            #region INotifyPropertyChanged Members
            public event PropertyChangedEventHandler? PropertyChanged;
            public void OnPropertyChanged(string propertyName)
            {
                if (PropertyChanged != null)
                {
                     PropertyChanged(this, new PropertyChangedEventArgs(propertyName));
                }
            }
 
            #endregion
        }

MyCommand

public abstract class ViewModelBase : INotifyPropertyChanged
{
    #region INotifyPropertyChanged Members
    public event PropertyChangedEventHandler? PropertyChanged;
    public void OnPropertyChanged(string propertyName)
    {
        if (PropertyChanged != null)
        {
             PropertyChanged(this, new PropertyChangedEventArgs(propertyName));
        }
    }
 
    #endregion
}

Model

class MyModel
{
    
    public Visibility myVisibility;
 
}

ViewModel1

public class MMViewModel: ViewModelBase
{
    public System.Windows.Visibility MyVisibility
    {
        get { return M.myVisibility; }
        set
        {
            M.myVisibility = value;
            OnPropertyChanged(nameof(MyVisibility));
        }
    }
}

ViewModel2

private ICommand myCommand;
        public ObservableCollection<MMViewModel> mm1;
        
        public ObservableCollection<MMViewModel> MM1
        {
            get { return mm1; }
            set
            {
                mm1 = value;
                OnPropertyChanged(nameof(MM1));
            }
        }
 
        public ICommand MyButtonClickCommand
        { get { return myCommand; }
            set { myCommand = value; }
        }
        public MyVievModel()
        {
            MM1 = new ObservableCollection<MMViewModel>();
            MM1.Add(new MMViewModel
            {
                MyVisibility = Visibility.Visible
            });
            myCommand = new MyCommand(ChangeVis, ToEvaluate);
 
            //LabelCommand = new MyVievModel(o => MainLabelClick("MainButton"));
        }
        private void ChangeVis(object context)
        {
 
            MM1[0].MyVisibility = Visibility.Hidden;
        }
        private bool ToEvaluate(object context)
        {
            return true;
        }

XAML

                <StackPanel>
                    <ItemsControl ItemsSource="{Binding Path=MM1}">
                        <ItemsControl.ItemTemplate>
                            <DataTemplate>
                                <Grid Background="Black">
                                    <Grid.ColumnDefinitions>
                                        <ColumnDefinition/>
                                        <ColumnDefinition/>
                                    </Grid.ColumnDefinitions>
                                    <Border BorderBrush="Blue" BorderThickness="2"
                                      Grid.ColumnSpan="2"/>
                                    <StackPanel>
                                        <Button Grid.Column="0" VerticalAlignment="Center"   
                         Content="What is Netflix?"
                                           FontSize="30" Foreground="White" Command="{Binding 
                        MyButtonClickCommand}">
 
                                        </Button>
                                        <TextBlock Grid.Column="1" HorizontalAlignment="Right" 
                                        Text="+"
                                           FontSize="60" Foreground="White">
                                        </TextBlock>
                                        <StackPanel Margin="0 5 0 0" Visibility="{Binding ChangeVis, 
                                Mode=TwoWay, UpdateSourceTrigger=PropertyChanged}">
                                            <TextBlock Foreground="White" 
                             FontSize="20">Text1<LineBreak/> Text1 continue</TextBlock>
                                            <TextBlock Margin="0 20 0 0" Foreground="White" 
                                    FontSize="20">
                                        Text2
                                            </TextBlock>
                                        </StackPanel>
                                    </StackPanel>
                                    
                                </Grid>
 
                            </DataTemplate>
                        </ItemsControl.ItemTemplate>
                    </ItemsControl>
                </StackPanel>

If you have some tips about how to improve my code - it would be very good! Thanks for your tips and comments!

The simplest MVVM solution would be to name the StackPanel and change its visibility from code-behind:

<StackPanel x:Name="ElementHost>

</StackPanel>
<Button Click="OnClick" />

private void OnClick(object sender, RoutedEventArgs e)
{
  this.ElementHost.Visibility = Visibility.Hidden;
}

If you need the value in your view model class you can bind the Visibilty property to a bool property and use the BooleanToVisibilityConverter class:

MainWindow.xaml

<Window>
  <Window.Resources>
    <BooleanToVisibilityConverter x:Key="BooleanToVisibilityConverter" />
  </Window.Resources>

  <ListBox SelectedItem="{Binding SelectedItem}">
    <ListBox.ItemTemplate>
      <DataTemplate>
        <StackPanel Visibility="{Binding IsEnabled, Converter={StaticResource BooleanToVisibilityConverter}" />
        <Button Command="{Binding RelativeSource={RelativeSource AncestorType=ListBox}, Path=DataContext.ToggleIsEnabledCommand}" />
        </StackPanel>
      </DataTemplate>
    </ListBox.ItemTemplate>
  </ListBox>
</Window>

MainWindow.xaml.cs

partial class MainWindow : Window
{
  public MainWindow()
  {
    InitializeComponent();
    this.DataContext = new MainViewModel();
  }
}

MainViewModel.cs

class MainViewModel : INotifyPropertyChanged
{
  public ICommand ToggleIsEnabledCommand => new ToggleIsEnabledCommand(ExecuteToggleIsEnabledCommand, commandParameter => true);

  // TODO::Raise PropertyChanged event
  public object SelectedItem { get; set; }

  private void ToggleIsEnabledCommand(object commandParameter)
  {
    (this.SelectedItem as ItemModel).IsEnabled ^= true;
  }
}