If you do see items listed in the Network properties window, you have at least some networking software installed. Look in the lower part of that window. Click once on that button. If Microsoft's File and Print Sharing software is not installed, you'll be asked if you want to install it. Checkboxes at the left show whether each feature is turned on.
File sharing is the option that is most dangerous on the Internet.
You can turn off File and Print Sharing completely using the checkboxes a good choice if the only network you connect to is the Internet. Next week we'll finish this series by seeing how you can continue to use File and Print Sharing without endangering your files.