Hostname for WHM installation with no top-level domain

If you are going to host emails on this server too and looking to send emails to the outside world, make sure you have proper hostname and is pointing to your server IP else emails won't work properly.

What you can do is to just add an A record entry in your schools domains DNS zone file which will point to the IP of your new server. Say, your school website name is yourschool.com (which is hosted elsewhere), so just ask the provider their to add an A record entry like internal.yourschool.com to point to your new server IP. Then you can use internal.yourschool.com as the hostname of your new server which will work fine.

However, if you are not looking to host emails, it is fine to leave the hostname as it is but make sure you don't use the hostname in accessing anything as it will lead nowhere.