Person.cs

using System.Collections.ObjectModel;
using System.ComponentModel;
using System.Runtime.CompilerServices;


namespace Katas
{
    public class Foo
    {
        public ObservableCollection<Person> People { get; } = new ObservableCollection<Person>
        {
            new Person {FirstName = "Johan", LastName = "Larsson"},
            new Person {FirstName = "Bug", LastName = "1000"}
        };
    }

    public class Person : INotifyPropertyChanged
    {
        private string firstName;

        private string lastName;

        public event PropertyChangedEventHandler PropertyChanged;

        public string FirstName
        {
            get { return this.firstName; }
            set
            {
                if (value == this.firstName) return;
                this.firstName = value;
                this.OnPropertyChanged();
            }
        }

        public string LastName
        {
            get { return this.lastName; }
            set
            {
                if (value == this.lastName) return;
                this.lastName = value;
                this.OnPropertyChanged();
            }
        }

        protected virtual void OnPropertyChanged([CallerMemberName] string propertyName = null)
        {
            this.PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propertyName));
        }
    }
}

wpf8b.xaml

<Window x:Class="Katas.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
        xmlns:local="clr-namespace:Katas"
        xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
        Title="MainWindow"
        Width="525"
        Height="350"
        mc:Ignorable="d">
    <Window.DataContext>
        <local:Foo />
    </Window.DataContext>
    <Grid>
        <ListBox HorizontalContentAlignment="Stretch" ItemsSource="{Binding People}">
            <ListBox.ItemTemplate>
                <DataTemplate>
                    <Border BorderBrush="Green" BorderThickness="1" Margin="0,3,0,3">
                        <Grid>
                            <Grid.RowDefinitions>
                                <RowDefinition Height="Auto" />
                                <RowDefinition Height="Auto" />
                            </Grid.RowDefinitions>
                            <Grid.ColumnDefinitions>
                                <ColumnDefinition Width="Auto" />
                                <ColumnDefinition Width="*" />
                            </Grid.ColumnDefinitions>
                            <TextBlock Grid.Row="0"
                                       Grid.Column="0"
                                       Text="First Name" />
                            <TextBox Grid.Row="0"
                                     Grid.Column="1"
                                     HorizontalContentAlignment="Stretch"
                                     Text="{Binding FirstName}" />
                            <TextBlock Grid.Row="1"
                                       Grid.Column="0"
                                       Text="Second Name" />
                            <TextBox Grid.Row="1"
                                     Grid.Column="1"
                                     HorizontalContentAlignment="Stretch"
                                     Text="{Binding LastName}" />
                        </Grid>
                    </Border>
                </DataTemplate>
            </ListBox.ItemTemplate>
        </ListBox>
    </Grid>
</Window>