If you want to watch over the air TV and your TV has a built in tuner you would connect the antenna to the RF antenna input on the TV (not HDMI), select over the air TV and run a channel scan.
If the TV doesn't have a built in tuner you could get a digital converter box but you need one with an output that will connect to the TV other than HDMI. Component video would still get you HD. Composite video would not.