If your test bookings have been cancelled and archived, they're as close to deleted as they can get – bookings can't be permanently deleted. They should only show up in the Bookings report at that point, but you can exclude them there as well. In the search fields for generating a report, click the "flags and status" field. In that field, you can select Pending and Received to report only on bookings that have not been cancelled.
If you haven't cancelled your test booking, you should do so as soon as possible to avoid being billed for it. You can find more about cancelling bookings here: https://www.rezgo.com/support-article/cancel-bookings