You should be able to print PDF through the driver over a network, from USB at the front panel the file has to be a TIFF or JPEG. These models only have a 1GB hard drive, make sure you are not trying to send a job too large to be processed.
You can download the driver directly from HP.com or use the CD that was included with the printer. The Designjet Utility is a desktop app that allows you to see the status of the printer, paper and ink levels. Along with any alerts or notifications, the DJ Utility will not play a role in being able to print. It is more for comfort of the operator to know status of the printer without having to physically go and check the front panel.
Without the driver, you cannot print on the T830.