any clue on the following, just created brand new site collection on-prem VM when browsed the new site collection on browser i get the following.
HTTP/1.1 200 OK Server: Microsoft-IIS/7.5 Date: Mon, 13 Feb 2017 21:43:37 GMT Connection: close
First make sure your URL hostname is pointing to correct IP address (i.e. your SharePoint server and IIS is listening to this IP and port).
Since you mentioned it is brand new site, I assume there is no harm to reset.
I guess your web application is not setup correctly. I suggest you first delete your site collection, delete all web application, then create web application and site collection again. Process the deletion and re-create within your CA. Do not change the IIS manually.