If I want to host websites, what can I choose

If you want to host websites, the best soloution will be cPanel.It has an easy to manage...

 What OS should I choose

This all depends on what you want to do with the server and how familiar you are with the OS.

 What Operating Systems are offered with cloud servers

We offer various operating systems for the cloud servers.Windows OS: Win2008 R2 Win2012 R2...