All your sent and recieved file transfers are listed in your transfer history. To view your transfer history, just log into your profile (upper right corner) and scroll down to view your timeline. Or hit the ‘History’ button in the bottom center of the screen.
On the left hand side of the screen you will see all uploads that you have done over the past. Each upload can be edited (e.g. delete files) by clicking on the transfer, unless the upload has already expired.
The right hand side of the screen shows any transfers that have been sent to you (as a downloader). These too are nicely listed here from newest to oldest. Just press any download (unless expired) in order to download it. In case you have not yet downloaded a transfer it will be listed as ‘NEW’. So you can easily see which transfers are the ones that you haven’t downloaded thus far.