Indeed they all suck and will let just about anything through these days unless you otherwise hobble your system by having to OK every action or doing the whole whitelist thing.
Windows Defender or whatever the old MS essentials is known as this week.
Make sure to install adblock and teach the people you are installing it for a good porn site, a good torrent site and how to use youtube-dl. Might also pay to figure out what they want to do and at least install an open source take on that. If you can try to install some common sense on top of that then such things are also good, and you can probably make some good money doing that such that you don't have to worry about antivirus.