Do I have 5G or 2G

Some devices cannot connect to some Wireless Routers/Access Points that are broadcasting the same SSID on both 2.4 GHz and 5 GHz bands, which is the way the Gateway is configured to operate.  You can change the SSID for one of the bands so that you can select which band you are connecting do via a specific SSID.  Do this on the gateway (http://192.168.1.254 ) on the Home Network > Wi-Fi page, under Advanced Options.

Most are both

Honjak, normally you have both only very very old routers do not support 5G, you can install Smart Home manager application from app store or  play store and check how your devices are connected and you can customize your 5G & 2G wifi bands, if that's you do not like you may login to the AT&T router/modem directly and check, however, I will suggest to go with app, in app once you are logged in you will have a tab named as Network, click there and you will find connected devices- once click on any device it will give you the info about wifi band to which the device is connected and than you may go to my wifi tab, also if you are using any of the following router/modem you surely have both band BGW320, BGW210 & 5268AC

Thank you, I really appreciate the advice. I have a BMG 320 from Att and thought it had both but couldn’t figure out how to connect my tv. I’ll try your solution. 

Oops bgw320 is what I have.