I understand that I will have two pages, one from AMP and the usual. AMP has a canonical reference to regular, but how does regular indicate that there is a version of AMP?
The AMP document discovery documentation indicates that you need to add this tag to <head> :
<head>
<link rel="amphtml" href="...">
As an example, if you look at the page of a publisher that already supports AMP, for example http://www.bbc.co.uk/news/world-europe-34471849 , you can see this tag in <head> :
<link rel="amphtml" href="http://www.bbc.co.uk/news/amp/34471849">