Assuming the antenna is an ATSC digital TV antenna it would have a F connector that would screw onto the antenna input of the TV. It will need to be positioned for best signal. You would then have to run a channel scan in the TV set up menu. With digital TV you can only watch channels that have been entered in memory during the scan.
If it's an old analog antenna it may prove to be useless or limit the channels that you can receive. If the antenna doesn't have an F connector but just two wires you will need a 300 to 75 ohm balun to connect it to your TV...