I think learning should be fun! And, for me, Microsoft made a lesson on learning how to do queries in Microsoft Power BI a lot of fun by using the query on the IMDB database. I love movies and I use the IMDb database often so I enjoyed the way the lesson categorizes movies.
Want to learn how to start using the Power BI tool? Well, you can either start by going to the Learn page at the Power BI website at https://powerbi.microsoft.com/en-us/guided-learning/powerbi-learning-0-0-what-is-power-bi/
Or, you you can go directly to the Power BI Desktop videos, and watch the short movies that also appear on YouTube. The IMDb example is at https://www.youtube.com/watch?v=ByIUx-HmQbw.
For folks that work with Dynamics GP 2016, these short learning sequences are a great way to discover the ease of creating Power BI reports from a data source.