You'll find the Wwise Adventure Game in the Wwise Launcher > Samples. Once it's downloaded, you can open both the Unity and Wwise project from there. If you don't see any Audiokinetic menu in Unity once you've opened WAG, something in the Unity initialization could have gone wrong. In that case, you can uninstall and install WAG, or simply delete the Library folder and reopen the WAG Unity project.
In regards to Wwise and Unity versions, using newer versions should not be a problem.
* Note that, if you are following the Wwise-251 or Wwise-301 courses, I'd advise you to use the same Unity and Wwise versions, to ensure that the course material steps will be accurate.
Hope this helps!