By default, a newly created page is unpublished and needs to be published before it is available to the general public. If you're on the site's console, you can see the status of the page while in Card View or List View. If you're in the page editor, you can check the status by clicking the Page Information icon in the upper left corner. The page status will appear in the gray text at the top of the menu.
Please note: if you need to delete a page, always unpublish it first. This ensures that the page will be unavailable to other pages that may be referencing it, and ensures that the page is completely offline and not cached by the system.