Yes, most companies will say that their meters are calibrated. And I suspect they are
once at the factory. pH pens tend to drift a little bit. The better more expensive ones hold calibration for longer. A bit of cal fluid is a nice backup and safety check. All you need is 4.0 and 7.0 fluid. A 2point calibration is far more accurate than a single. However, if you're on a budget I would pick up just the 7.0 for now. I've used these from biopharm:
Amazon product ASIN B01F7OXRG2
You also need storage solution as letting the glass bulb dry out will kill your meter. You cannot store it in tap, distilled, or other water solutions.
I have this one from Apera. $15-ish and has lasted over 2 years at this point and it beyond its expiration. I only had to put a few drops in the cap.
Amazon product ASIN B07NXTBD8D