They host either linux or MS.
Most of these sites will run under Linux, so that is probably the way to go. It won’t matter to you because you won’t be touching the “Linux” operating system once it is installed. Everything is done through “admin” or configuration pages built into the site ... so you do not need to do anything in Linux or know how to develop. And you can do all this right from your home PC through your browser. Whether you have Linux, Windows, or MAC does not make any difference.