To do that, find Appearance in your Dashboard and click on Nirvana Settings. Click on the section Layout Settings to see the options. Here you can chose your main layout. For your website you are going to select the first one, which is One column, (no sidebars).
Underneath you can adjust the content and the sidebar weight. Set the Content to 1000PX, Sidebar(s) to 400PX, and the Total width should be 1400PX. Leave the DUALITY option to be Wide
The last option is RESPONSIVENESS, which by default is enabled. Leave it that way and also check the box Allow zoom. That will make your website to automatically adjust the resolution and its size for whatever the mobile device is being displayed on, and it will also allow all users on mobile devices to zoom in and out.
If you refresh your website, you will see that the Right Side Bar is no longer visible.
In the next few steps you are going to configure the HEADER SETTINGS.