How to use or setup a google AMP cache for my amp website. I have seen many site manages their request from google.com server . How it is possible for me?
To make Google serve your pages as AMP-page, the page must be re-written / modified to make it fit the AMP requirements.
AMP-pages are stripped down versions of web pages, with some restrictions compared to ordinary websites. The HTML markup is slightly different, i.e. and there are other restrictions such as CSS limited to 100kb. Those sites are separately hosted and as soon as Google crawled it, it might be included in the AMP mobile search results.
See AMP documentation for the details on how to implement it.