Whenever sharing a page, you can decide if the author and the title will be visible or not in the Advanced Options:

You can manage those settings anytime and the changes will be applied to the shared page as soon as the page is refreshed. 

Additionally, you can decide if the title and author will be visible on a page level withing the application. Here, for example, this setting will be applicable only to the document you're editing: 

If you would like to always show the author for all documents inside your Craft app, you can enable it in your Craft Settings: