As a Pro user with a multi-page site, you'll be able to hide pages from your navigation menu on your published site. The hidden page will be still published, just not visible to visitors from your site navigation menu.
To select a page to hide, go into your page manager:
Click the setting gear of the page you want to hide and uncheck the "Show in navigation" menu:
Once the "Show in navigation" option is unchecked, you'll notice that the link to the page disappears from your site's navigation menu. The page will still be accessible through its URL here: