I'd say the minimum set of commands for Alexa are all listed in the Alexa app on your phone.
Just start the app, press the menu icon, then press Things to Try.
There, it will list several commands such as: What's in the news, Play some music to help me sleep, Stop the music, Turn it up, Next song, What Mexican restaurants are near by, Find the hours of a nearby bank, What's the weather, Will it rain tomorrow, Did Falcons win, What movies are playing, Play 97.3 FM on Tunein, etc.
These commands, and many more, are all listed in the Alexa app. You might want to check it out and write down some of the ones that are more useful to you.