Display Terminal message on login
I like the message of the day for this.  As tradition dictates...
me@Mac ~ % echo &quot;Welcome to the University of East Westia&quot; &gt; /tmp/motd
me@Mac ~ % sudo mv /tmp/motd /etc

Note: /etc/motd is only displayed in a login shell, which is typical of Terminal.app on macOS.  If you typically run non-login shells, you should handle display of /etc/motd in your shell dot files.