When USPS tracking says status not available it means that the tracking information has not got into the USPS tracking system yet.
The shipping label may have been created but the package may have not gotten to the USPS yet.
Give it a day or 2 days and then check again and the USPS tracking should update.
USPS tracking information is not very reliable even though the USPS is supposed to scan your mail when it's picked up or dropped off at the post office.
Sometimes they don't scan the packages or mail that have tracking numbers until the package gets to your local post office.
So I would wait at least a day or so and check again sometimes it will update and if not then contact the person shipping the package to find out what's going on or contact the USPS and provide them with the tracking number.
Usually it's just a case of them not scanning the tracking number and entering it into their system sometimes it happens.