AT&T's 5G network is finally up and running in one of the largest cities in the world - New York City. The catch is that even if you want to, you can't use it right now because it's only available for business customers.
Of course, the network is far from ready. It's only available in small spots throughout the city and uses the millimeter wave, which is quite fast but has limited range. Moreover, indoor connections pose a challenge.
A more practical implementation of the 5G will come in the following months on the sub-6GHz frequencies while nation-wide coverage should be expected in the first half of 2020.