Bar Chart at 1:41 in the video is not showing

can you please show me the relationship between the two tables?

I noticed that my column headers seem to be incorrectly recognized. For instance, there is the summation sign instead of the calendar sign on the dates.

In this case I would suggest you switch to the date format, I cannot see the column from factInternetSales that is used for the relationship 

I'm trying to figure out how to switch it to the date format. Can you guide me please

Please go back to Power Query and select the column that you want to change the data type for. Then if it is text you will see a little icon saying "a,b,c", click on the icon and select where it says date change it to date.