Help me understand how to read reports

[PawPrintPress]

1. I'm trying to see how much I've spent on supplies (buying materials from Ebay, Etsy, etc), but I can't tell. I thought creating a report of only the "Completed" transactions would make it easier, but nope. I've got 5 transactions for $11.11 (or -$11.11). Can someone explain to me how much I spent on filters?
2. Is there a location for this basic information in the Help section, because I've not been able to find any.