When the USPS tracking information says "Departed Shipping Partner Facility, USPS Awaiting Item" it means that the package has left the shipping partners shipping facility such as UPS and is gonna be delivered to USPS sorting facility.
Then the USPS will take over the shipping after the UPS drops the package off at the USPS.
UPS Sure Post is what your package is likely being shipped through if you've checked your UPS tracking and it gave you a USPS tracking number.
UPS Sure Post means UPS delivers the package to your local destination sorting facility and then USPS sorts it and puts it on the truck to be delivered to your local post office for delivery.
UPS sure post does not deliver to your package to your door but instead it gets handed off to the USPS for final delivery.