Change the device name
Having a name that is uniquely recognisable makes it easier to identify your system on the network and when pairing Bluetooth devices.
Open the Activities overview and start typing System.
Select Settings ▸ System from the results. This will open the System panel.
Select About to open the panel.
Select Device Name from the list.
Enter a name for your system, and confirm.
Although the hostname is changed immediately after the system name has been changed, some running programs and services may have to be restarted for the change to take effect.