Simple troubleshooting steps.

Is the terminal turned on?

A good indications is the screen is on.  If not push the on power button

Counter Display Terminal Toast

Is the POS connected to the internet?

Usually in the top right hand corner there will be a wi-fi symbol or network symbol.

Wi-Fi Symbol
Network Symbol

Is it on the correct network ip address?

Connect your laptop to your POS network. Right click on the internet access. Right click on Open Network & Internet settings

Right click on the Internet Access
Click on the connected network .
Scroll to Ethernet
Click on the network below Ethernet
Scroll down to IPv4 address