Войти, используя Xamarin форм с MVVM и базы данных SQLite

I want to login using Xamaring forms with MVVM and SQLite Database. I created a LoginModel.cs, LoginPage.xaml and LoginPage.xaml.cs.

My Questions are:
1. How can I create a local database?
2. How can I create, updated, edit and delete data to local database?<br/>
3. How can it automatically go to homepage if the username and password type is equal to the data inside the local database?


(Note: my codes are below)
LoginPage.xaml(This is where I bind my entry and button)

    <?xml version="1.0" encoding="utf-8" ?>
    <ContentPage xmlns="http://xamarin.com/schemas/2014/forms"
                 xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
                 x:Class="TBSMobileApplication.View.LoginPage"
                 BackgroundColor="#ecf0f1">
        <ContentPage.Content>
            <StackLayout 
                VerticalOptions="StartAndExpand">
                <StackLayout.Padding>
                    <OnPlatform 
                        x:TypeArguments="Thickness"
                        iOS="20"
                        Android="20,100,20,0">
                    </OnPlatform>
                </StackLayout.Padding>
    
                <Label 
                    Text="Username"
                    TextColor="#34495e"
                    Font="Arial,10"/>
                <Entry
                    Placeholder="Username"
                    PlaceholderColor="#95a5a6"
                    FontSize="12"
                    FontFamily="Arial"
                    x:Name="entUsername"
                    Text="{Binding Username}"/>
                <Label 
                    Text="Password"
                    TextColor="#34495e"
                    Font="Arial,10"/>
                <Entry
                    Placeholder="Password"
                    PlaceholderColor="#95a5a6"
                    FontSize="12"
                    FontFamily="Arial"
                    IsPassword="True"
                    x:Name="entPassword"
                    Text="{Binding Password}"/>
                <Button 
                    Text="Login"
                    FontSize="12"
                    HorizontalOptions="Start"
                    BackgroundColor="#3498db"
                    Command="{Binding SubmitCommand}"/>
            </StackLayout>
        </ContentPage.Content>
    </ContentPage>

LoginPage.xaml.cs (This is where the functions are executed)

    using System;
    using System.Collections.Generic;
    using System.Linq;
    using System.Text;
    using System.Threading.Tasks;
    using TBSMobileApplication.Model;
    using Xamarin.Forms;
    using Xamarin.Forms.Xaml;
    
    namespace TBSMobileApplication.View
    {
    	[XamlCompilation(XamlCompilationOptions.Compile)]
    	public partial class LoginPage : ContentPage
    	{
            public UserModel userModel;
    
    		public LoginPage ()
    		{
    			InitializeComponent ();
                userModel = new UserModel();
                MessagingCenter.Subscribe<UserModel, string>(this,"Login Alert",(sender, username) =>
                {
                    DisplayAlert("", username, "Ok");
                });
                this.BindingContext = userModel;
    
                entUsername.Completed += (object sender, EventArgs e) =>
                {
                    entPassword.Focus();
                };
    
                entPassword.Completed += (object sender, EventArgs e) =>
                {
                    userModel.SubmitCommand.Execute(null);
                };
    		}
    	}
    }

UserModel.cs(This is where I get the values and functions)

    using System;
    using System.Collections.Generic;
    using System.ComponentModel;
    using System.Text;
    using System.Windows.Input;
    using Xamarin.Forms;
    
    namespace TBSMobileApplication.Model
    {
        public class UserModel : INotifyPropertyChanged
        {
            public event PropertyChangedEventHandler PropertyChanged;
            public string username;
            public string Username
            {
                get { return username; }
                set
                {
                    username = value;
                    PropertyChanged(this, new PropertyChangedEventArgs("Username"));
                }
            }
    
            public string password;
            public string Password
            {
                get { return password; }
                set
                {
                    password = value;
                    PropertyChanged(this, new PropertyChangedEventArgs("Password"));
                }
            }
    
            public ICommand SubmitCommand { get; set; }
    
            public UserModel()
            {
                SubmitCommand = new Command(OnSubmit);
            }
    
            public void OnSubmit()
            {
                if (string.IsNullOrEmpty(Username) || string.IsNullOrEmpty(Password))
                {
                    MessagingCenter.Send(this, "Login Alert", "Please fill-up the form");
                }
                else
                {
                    MessagingCenter.Send(this, "Login Alert", Username + " & " + Password);
                }
    
            }
        }
    }

I can get the data I typed using a "**DISPLAYALERT**" through "**MessagingCenter**" from the text box. I don't know how to proceed in creating a local database to be able to login and go to the main page.