Where do you start with Power BI? Well this video is for the absolute beginner. You don't need any exercise files as you'll create your own in Excel. You'll then import the video to the only version of Power BI. After that you'll create a report using the Card, Table and Column chart visualisation. You'll see how to format the visualisation (change the colour of charts and generally make it look pretty) and do one or two cool interactions.
You don't need any exercise files as you'll create what you need as you go along.