Click on Home and Customization. Then click on Sell Settings then Sales History.
If you want to see your incomplete sales, simply click on Unconfirmed & Incomplete Sales.
Incomplete and unconfirmed course sales can happen for many reasons. For example, a user could have forgotten to click on their enrollment email, PayPal might need to verify their bank account before allowing purchases to be made, or their e-check is being held. If you want to allow users access to the course before payment has gone through, you can always manually mark them as paid.