The site configuration options content type itself does not appear on the page, but controls how other content items are displayed by giving users the option of keeping your website content at a fixed width (1170 pixels wide), or opting to convert your pages to full width.
In your "Section Customizations" folder, you should find a "Site Configuration Options" content type, and within that content item, you can easily select between a fixed width or full width style for all of your pages.
If you decide to convert your pages to full width, you may find that some of your older images will need to be replaced with higher resolution images in order to look good on larger or wider screen sizes. Please see our guidelines for Working with Images on how to optimize your images for the web.
If you have any questions about converting your pages to full-width, please let us know.