Have you ever tried to save changes to published posts in WordPress without publishing the content? The default install of WordPress does not allow you to save draft copies of published items. You could always Un-publish the page however it will disappear from your site until you Publish it. This video shows you how to install a plugin called revisionary that provides this capability.
If you want to create a WordPress site and do not have the technical knowledge or skill to install and configure all the plugins that will ensure your site is successful, then why not check out our Managed WordPress plans. In the mean time we hope you get some benefit from the video.