Enabling Type to be used as Default Page in Plone 5
                   How to enable a type to be used as a default page from the "Select a content item as default view" menu in Plone. 
                
            
            
        
                             
                             Go to yoursite.com/plone_control_panel
Click "Content Settings"
Select your type from the top drop down menu.
Tick the "Can be used as a default page" box and press save.