My new WD Passport created a double backup

I bought a new WD Passport. I have used several previously. they are easy to use. However, while downloading the first backup for this specific drive, my PC went in sleep mode.

When I clicked back, my WD Passport on the screen stated something like “failure to complete.” So, I started a new backup, which successfully completed.

However. it turns out, I now have two complete backups that are duplicated. Both are almost 0.8 T Not only is that a waste of space on a 4T external hard drive, but what happens going forward?
Will both update with the same new files?
How do I delete one of the backups?
Or can I delete both and start fresh with a new clean backup?
Thank you to anyone who can help?