Hi Tom,
The Wwise Adventure Game Unity project should work just fine. However, for using Wwise you should probably download the latest version "Wwise Adventure Game 2019.2.5" which is compatible with Catalina.
That said, if you are following the Wwise-251 or Wwise-301 certification, you would need to download WAG 2019.1.4, and then use a newer version of Wwise that is compatible with Catalina, like Wwise 2019.1.10. As long as you're just using a newer minor (2019.1.x) version, you should be quite safe.