Hamburg comes with two page templates you can manually activate. You’ll find them, as usual, in the meta box Attributes when you edit or create a page.

The first template is named Full Width. It displays your page content without a sidebar in one single column of 745 Pixels width maximum.

The second template is named Sidebar Left. It displays the sidebar on the left side of your page content.

You can always add your own page templates when you create a Child Theme.