To create the main navigation, you'll need to follow a certain naming convention. Say, if you want to add Shop to you menu, you'll have to say Shop/Browse collections. Anything after the "/" will be the tagline for the menu. The same navigation will be used for mobile, however, the tagline will not be displayed.
Menu name format: [Title]/[Tagline]
Once you create a page, change the template to page.contact using the page settings.