How to configure my modern Tv to pick up broadcast channels?
Over the air (OTA) broadcasts are all digital now, so you will likely want to scan using the Digital tuner option, probably starting with "STD".

You likely will need an antenna.  antennaweb.org can help you select the proper type of antenna to get the most channels and provide some information on how it should be aimed.  I believe that most antennas will connect into the same connector on the TV that you used for the cable TV cable.

Once you get everything set, you should be very happy with the results.  The HD broadcasts that are sent OTA are very high quality.