In advance of Saturday morning’s disabling of the AFP file-sharing protocol, please disconnect from the server at the end of your workday today (Friday). The simplest way is to log out of your computer.
If, however, you would like to continue to use your computer for non-file server tasks (email, web, Teams, etc), ensure your computer is disconnected from the server. Disconnect (eject) all server instances from the Finder sidebar as shown below. You might only see one instance.
You may reconnect to the file server anytime after 10:00 am on Saturday.