I hope that's satire antivirus are useless, unless you're using a hardware firewall, please don't.
Otherwise, use Tails preferably with a disposable device's or public owned one.
Idk. I started getting Windows notifications about McAfee which I immediately clicked and they asked me to call a number. I kind man with an Indian accent asked me to transfer $3000 which I felt was reasonable. He said thank you very much and I'm protected. I don't see McAfee anywhere on my machine but I assume it's just hiding so viruses can't tell it's there.
Sure that's an option, preferably pfSense, it's the longest standing & most advanced.
In ordinary time it should be mandatory for every person to have one, not when shit hit the roof.