How to create a fact table?

Hi there, 

So I have a big Excel sheet and I split the different columns into multiple dimension tables to eventually create a star model.

I now have 7 dimension tables with some tables having just between 3 and 10 rows, while some tables have between 50.000 - 200.000 rows.

I want to have 1 fact table with inside of it the amount of products sold and all the other columns existing of foreign keys. How can I do this in Power BI?

Here is an example of what I want to recreate:

So the table below is my fact table (the first three columns are the foreign keys which are the primary key in their own dimension table.

What is the best way to do this in PowerBI? I have never done this before...

Thanks for your help!