I am getting a message from Norton that my home network has been attacked and that I should stop using it. How do I get details?

I have some important thoughts to share. I assume that your home network is the Wi-Fi network, It is protected by a password. You can change that password to a more complex one to increase safety and that should be sufficient. Second, completely uninstall Norton. Use the uninstall app on their web site to completely remove all of it. It is completely unnecessary. The Mac has built in antivirus protection and its operating system is write protected, so it can't be infected. Norton will slow your computer down substantially and often causes other serious problems, as has been detailed on this forum many, many times.