Google AMP is designed for improving the mobile experience for your site by showing a stripped down version of your site. There are pros and cons for setting this up for your site but it would depend on personal preference for if you should add it.
For installing the AMP plugin go under Plugins, Add New and find the AMP plugin.
Under Appearance, AMP you will be able to customize the look of your site for when users view it on mobile.
There are multiple customization options including colors and logos for the new reduced page of your site for mobile.
Once you have it designed how you would like, ensure you save your changes.
Should you want to preview the AMP page from your computer you would go to the post and add /amp to the end of the url.
Using the Yoast SEO plugin you are able to customize the design, colors, and other options for your AMP pages.