Caller ID is an included feature with Cableone phone service. It should be working automatically. I'd call Cableone phone support to make sure they have it active on your account. If they claim it should be working and isn't, then I'd suspect a phone problem. I've seen caller ID supported phones not work for one reason or another. It would be time to try another phone to make absolutely sure it's not a phone problem.
I had Cableone phone for about a year before cancelling due to poor service, but I never had problems with the caller ID feature. As long as the phone service was up and working... the caller ID feature worked flawlessly.