Not sure what brand TV you have but setting it up for cable should be fairly easy. No need to hit buttons on the rear of the TV.
You've already verified your connected to the cable outside.
Turn the TV on. Take the TV remote and hit the menu button while pointing it at the TV. In the menu you should fine the option to change the antenna setting to cable. Change it to cable then run a scan to get all the cable channels. Once this is done, exit the menu screen and select whatever channel you would like to watch.