Purchase order and Sales analysis

I have very little knowledge about how to analyze purchase or sales orders and need to calculate

1. "how many purchase orders are not filled?"  What exactly does "filled" mean? Is it the status of PO? 

2. sales performance data for the year sliced by month, quarter and by sales person

I could show sales by salesperson by month or quarter not both on PowerBI. Any other way I can show this?

3.Also how to show "Geocentric data points (Where are we doing great in sales)"?

Could someone please throw some light on this question(with the help of some sample dashboards)?

The data is MS access default template for Northwind db.

Thank you!