Is there a way from the server side to determine if the page being loaded is within an iframe, our a stand alone page? Is there a head or something that tells you it's within an iframe without the client telling you.
Not really.
If your page is being loaded in an iframe, the URL of the parent frame will be in the Referer
header (unless referrer policies prevent it from being sent). However, the same thing will happen if your page is being loaded as the result of the user clicking a link on the source page -- there's no way to tell the two apart from the server side.