WordPress 5.0 introduces a new editor for the content named Gutenberg.
We’ve been using a Page Builder by SiteOrigin plugin for years in our themes and all our themes rely on it. For the time when we’re migrating our themes to be Gutenberg-compatible, you can get the old classic editor experience with Page Builder by installing the Classic Editor official WordPress plugin.
TIP: If you’ve never installed a WordPress plugin before, here is a quick guide.