In Katana, you can export both Open and Done Sales orders into a .csv or .xlsx file.
Navigate to the Sell screen and choose the Open or Done table depending on which you wish to export.
You can find the Export button at the top corner of the order list. This will export all orders on the list.
Each row in the exported file is one order line, not a full order. If you have more than one line on an order, there will be multiple rows for this order in the exported file. This enables you to analyze sales at the product level.