The hostname of your laptop is the label that we give it to be able to identify the device physically and on our network. This is helpful for us to keep track of devices and also remotely access laptops when needed for troubleshooting.
The label can be found on top and the bottom of the laptop. It should start with STL then have 3 identifying numbers after it. An example would be STL500.
If the labels have come off you can find the hostname by opening settings. In the System section at the top of your screen you should see your device name which is the same as the hostname.