By default all pages in WordPress use the 'page.php' template file to format the structure. If you want to setup a different template structure that can be re-used for multiple pages, follow the steps below.
Now you can start editing this file to your requirements.
To use the new template, login to the admin panel and go to the page you want to assign the template to. You'll notice that your new template has now been registered in the 'Page Attributes' section on the right hand side under the 'Template' drop down.
You can use the template on as many different pages as you want.
Read more about page templates in the WordPress Codex.