Using the Desktop
UEA Linux Desktop 18.04 is based on Ubuntu 18.04.
By default it uses the Unity desktop environment (a substantial change from the old Gnome desktop). All the following information is about the unity desktop version.
You can select the Gnome Classic desktop from the login screen for a more familiar environment, but it is worth spending some time becoming familiar with the new desktop - you may prefer it.
The design is intended to make heavy use of the keyboard, to reduce the number of times the user must switch between keyboard and mouse. There are webpages that explain it in detail but it's worth remembering that if you hold down the Super key (on most keyboards that's the Windows key) for several seconds, a cribsheet pops up to show the most common shortcuts.