✅ Not Quite Understanding Model Usage

public class UserModel
{
  public int Id {get; set;}
  public string FirstName {get;set;}
  public string LastName {get;set;}
  public string Email {get;set;}
  public string Username {get;set;}
  public string Password {get;set;}
  public int TosAgree {get;set;}
  public UserCustomSettingsModel CustomSettings {get;set;}
}

public UserCustomSettingsModel
{
  public UserStylesModel UserStyles {get;set;}
  public UserSettingsModel UserSettings {get;set;}
}

public UserSettingsModel { public int UseOnlineStorage {get;set;} }

public UserStylesModel
{
  public string FontSize {get;set;}
  public string FontStyle {get;set;}
  public string FontColor {get;set;}
  public string BackgroundColor {get;set;}
  public string BorderColor {get;set;}
}

public partial class TosViewModel : ViewModelBase
{
  public void SetupUI()
  {
    FontSize = User.CustomSettings.UserStyles.FontSize;
    FontStyle = User.CustomSettings.UserStyles.FontStyle;
    Foreground = User.CustomSettings.UserStyles.FontColor;
    Background = User.CustomSettings.UserStyles.BackgroundColor;
    Border = User.CustomSettings.UserStyles.BorderColor;
    Border2 = "#CDCDCD";
  }
}