There are several places where pages can be named in Sitecore. How the name fields are approached impacts how the name displays within the system and publicly to website visitors.
When initially creating a page, use lowercase letters and a hyphen or underscore instead of a space in the page title. This initial name impacts the page URL and appears in the Site Content Tree.
To change how the page name appears in the Site Content Tree within Sitecore:
In Pages:
Click Rename. The Site Content Tree now shows the new Display name.
To change the visible page name that is referenced in the Main Navigation, Page Title and Contextual Navigation components:
In Content Editor: