MysteryMachine,
Hope you are enjoying your new FIOS Internet. Since they said your phone is part of Freedom Essentials, it's the traditional voice service (PSTN), however you should have CallerID which I got part of Freedom essentials ( recently got my FiOS Triple play installed and I got CallerID, Voicemail and free long distance part of the voice package). Based on what I heard FiOS Digital Voice is in market trials and is not available nationwide. I recommend you to call customer service and confirm.
Cheers