How to properly install AMP plugin to wordpress site ?

Yesterday I messed around with AMP for the first time on a wordpress site of mine. I installed this plugin https://wordpress.org/plugins/amp/ and then I installed this https://wordpress.org/plugins/glue-for-yoast-seo-amp/ plugin.

Is that all I have to do ? And when I did this this blog was already established with content on it, does this only effect posts/pages I do after installing the plugin ? And does AMP "help" homepages at all or only posts ?

Take a look at this...https://www.wpbeginner.com/wp-tutorials/how-to-properly-setup-google-amp-on-your-wordpress-site/