Example of how to implement local database in your Xamarin.Forms applications - http://julianocustodio.com/litedb

MainPage.xaml

<?xml version="1.0" encoding="utf-8" ?>
<ContentPage xmlns="http://xamarin.com/schemas/2014/forms"
             xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
             xmlns:local="clr-namespace:DemoLiteDB"
             x:Class="DemoLiteDB.MainPage" Title="Demo LiteDB">

    <StackLayout Padding="10">
            <Entry x:Name="EntryName" Placeholder="Name"/>
            <Button Text="Insert" Clicked="Insert"/>
            <Button Text="Get" Clicked="Get" />

            <ListView x:Name="ListCustomers" ItemSelected="List_Selected">
                <ListView.ItemTemplate>
                    <DataTemplate>
                        <ViewCell>
                            <StackLayout Orientation="Horizontal" Padding="10">
                                <Label Text="{Binding Id}"></Label>
                                <Label Text="{Binding Name}"></Label>
                            </StackLayout>
                        </ViewCell>
                    </DataTemplate>
                </ListView.ItemTemplate>
            </ListView>
    </StackLayout>

</ContentPage>