exam_prepare/Pages/order.xaml

<Page x:Class="examPrepare.Pages.order"
      xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
      xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
      xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" 
      xmlns:d="http://schemas.microsoft.com/expression/blend/2008" 
      xmlns:local="clr-namespace:examPrepare.Pages"
      mc:Ignorable="d" 
      d:DesignHeight="450" d:DesignWidth="800"
      Title="order"
      Background="white">

    <StackPanel>
      <Label Content="Заказ"/>
      <TextBlock Text="номер"/>
  </StackPanel>
</Page>