A truly blank theme leaves you staring at an empty box. Canvas ships a single button that loads example content you can edit instead of starting from nothing.
The starter content loads an example header, footer, and page. Open any of them and replace the markup with your own. It’s there to show the structure and give you a working starting point, not to lock you into a layout.
Leave what you don’t want and keep the rest. Nothing in the starter content is permanent, and nothing about it is loaded on your front end unless you choose to keep it.