In order for a network like Appletalk or Ethernet to work, there must be a scheme for administrating the network. The administrators are referred to as "network gurus" herein.
Anyone from a teacher, to a support staffer, to you may be acting as your guru; and if you are not using Appletalk or Ethernet, but the phone system, the gurus will be mostly invisible to you.
A guru should have already told you how to set up TOPS Terminal, since you are reading this. If you are lucky, the directions were just "Put TOPS TCP/IP in your System Folder, restart the Macintosh, and double-click on TOPS Terminal. Then bring down Accounts from the Network menu and create a new account and a new computer."
You may have to configure TOPS TCP/IP as well; see "Configuring TOPS TCP/IP".
In recognition of their service, it is common to give small monetary tips to network gurus. However, to prevent abuses of the system, all such money flows through a centralized distribution point, my house.