AMP support is integrated via official AMP for WordPress plugin (built by Automattic), available for free download in the wordpress.org repository. You can also install it directly from the WP admin ▸ Plugins ▸ Add new. After installing the plugin you can find the AMP specific options in Customizing ▸ AMP ▸ Design.
To control Mobile settings go to Customizing ▸ Mobile. You can Control Global options and Header Options. Global Header In header section you can control Composition of Mobile Header, add or remove Components, make mobile header Sticky, upload Mobile Logo, and set Background color and Text Color for Mobile Header.