In case you are looking to disable the sidebar or widget bar, It’s as simple as removing all the widgets from Admin > Appearance > Widgets > Click the widget > Delete. This result will be same like my current template.
Using my second way, which I wouldn’t recommend is to comment out the following code from your template files.
<?php get_sidebar(); ?>
Using my third way, we will be making use of Stylesheet (style.css). Just add the the following code into the file and reload your blog after clearing your previous cached styelsheet.