Virtual hosts, host alias equivalents and LetsEncrypt SSL for IIS on Windows Server

The equivalent of adding virtual hosts in Apache is adding Sites in IIS. And similar to adding a host alias, what is done is to add a site binding. IIS Manager -> Servername -> Sitename -> Edit site 

Then, getting SSL certificates from LetsEncrypt and applying them - 
https://weblog.west-wind.com/posts/2016/feb/22/using-lets-encrypt-with-iis-on-windows
suggests using LetsEncrypt-Win-Simple which is now WinAcme. Very simple interactive script as described on their website.

Also, various possible reasons for IIS errors are listed at https://superuser.com/questions/741486/page-not-found-in-iis-but-its-there