I\'m using Visual Studio 2017 on Windows 10 with no Mac at all. When I try to debug a new Xamarin cross platform project, VS tries to locate a Mac.
Is a Mac pretty much
Yes you will need a Mac. It's not so much a limitation on Xamarin as it is a restriction by Apple to make people buy their hardware.
Regardless of if you are looking to tinker, ship an app or set up a build pipeline, your best option is something like MacinCloud or a Mac Mini (i.e. something on your local network).
UPDATE: During the Build 2017 conference, Xamarin Live Player was announced!