When you create a page through the WordPress dashboard, you just choose ‘Default Template’ as the page template in Template dropdown under ‘Page Attributes’ section. This section is on the right below ‘Publish’ section.
By default, the page has right sidebar. Probably you are not seeing it because you have not dropped any widgets into the widget area named ‘Primary Page Sidebar’ or the ‘Secondary Page Sidebar’ widget area. Pls check. Thanks