lab1/WpfApp1/MainWindow.xaml

<Window x:Class="WpfApp1.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:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
        xmlns:local="clr-namespace:WpfApp1"
        mc:Ignorable="d"
        Title="MainWindow" Height="450" Width="800">
    <Grid ShowGridLines="True">
        <Grid.RowDefinitions>
            <RowDefinition Height="auto"/>
            <RowDefinition />
            <RowDefinition Height="auto"/>
        </Grid.RowDefinitions>
        <Grid.ColumnDefinitions>
            <ColumnDefinition Width="200"/>
            <ColumnDefinition/>
        </Grid.ColumnDefinitions>

        <!-- типа логотип компании -->
        <Image 
        Source="./assets/Guitar.jpg" 
        Grid.RowSpan="2" HorizontalAlignment="Right"/>
    <DataGrid
    Grid.Row="1"
    Grid.Column="1"
    CanUserAddRows="False"
    AutoGenerateColumns="False"
    ItemsSource="{Binding GuitarList}">
        <DataGrid.Columns>
            <DataGridTextColumn
            Header="Бренд"
            Binding="{Binding Brand}"/>
            <DataGridTextColumn
            Header="Модель"
            Binding="{Binding Model}"/>
            <DataGridTextColumn
            Header="Цвет"
            Binding="{Binding Color}"/>
        </DataGrid.Columns>
    </DataGrid>
        <StackPanel 
        Orientation="Vertical"
        Grid.RowSpan="3"
        VerticalAlignment="Bottom">
            <Button 
            x:Name="ExitButton"
            Content="Выход" 
            Click="ExitButton_Click"
            Height="50"/>
        </StackPanel>

        <WrapPanel
        Orientation="Horizontal"
        Grid.Column="1"
        MinHeight="50">
            <!-- минимальную высоту я тут поставил, чтобы верхнюю строку сетки было видно. В реальном приложении она не нужна -->
        </WrapPanel>
    </Grid>
</Window>