By default the blog always will displayed on the front page but what about the other page of your site that you want to display without the sidebar. Changing it is actually quite easy and if you go to your Dashboard and click on > Settings > Readings your see there is options of display different options about front page.
Go to Pages and select Add New to create a new page and simply called it blog. Put any information here and not do anything with layout. Now go back to Settings and Readings and change the static page and now set front page to your newly created Blog page and save the settings.
Simply changes the content on your front page you can changing the whole look and layout of the website and you are giving a visitor and indications what is important.