I think I got it working. I uninstalled MySQL 8.0, installed 5.7.23. Ran the wordpress setup again and it works. HudsonValleyWebDesign’s answer got me on the right track. Thanks!
Hmm… I’m gonig through the steps for the link you sent. It seems like the WordPress install wizard from the Web Platform Installer is looking to install MySQL 5.1. Maybe 8.0.12 isn’t supported.