This website, TV Fool:
https://www.tvfool.com/?option=com_wrapper&Itemid=29
It will tell you what free channels are available at your location and from what direction and what size and type of antenna you will need
All over the air channels are digital now, so to get PBS you must have a digital tuner
Digital channels still use Analog Carriers, VHF are channels 2 to 13, these go farther but need a larger antenna for the longer waves
UHF, channels 14 to 83, don't travel as far, are cheaper to broadcast and use shorter waves so can use smaller antennas
UHF is, of course, the most popular for broadcasters, lol
An analog carrier can have 1 to 8 digital channels on it, that's where the digital tuner comes in, it tunes the analog carrier, like channel 3 or 33, then looks for a signal that tells it how many channel "packets" are in the carrier and what format to use to "decode/unpack" them