A warning about this: There is no such thing as different antennas for analog and digital. The different antennas are UHF and VHF. "Digital antenna" was just marketing sugar used to try to get people to buy UHF antennas to receive digital channels, which, prior to June 12, 2009, were almost exclusively on UHF. And especially since June 12, 2009, many (though not most) digital channels are on VHF, so antennas that are sold as "digital antennas" won't actually do the trick. In many areas, you need combo VHF/UHF antennas. The plot that the OP would get from the LINK I provided above or the link that DrCavin provided earlier will show what antenna is needed.
1) Buy a set top (Indoor) UHF/VHF antenna (make sure it is UHF/VHF, not UHF only)
2) Read the assembly directions for the antenna
3) Connect the antenna cable to the "TV IN" spigot on the back of your TV
4) Hit MENU on your TV, there should be an option called "ADD CHANNELS" or "FIND CHANNELS" or "SCAN CHANNELS". Push that option.
5) When it's done, see how many stations you have. If you don't know how many over the air TV stations there are in your are, GOOGLE (your city name) TV stations, or the closest major city, write down those channel numbers. Check and see if you have them all.
6) If you do not have them all, or any channels, you may need to move the antenna to get a signal. Hit MENU again on your TV, there should be a "SIGNAL STRENGTH" option. Select than, then move the antenna around until you get the strongest signal. Go back to step 4. You may have to repeat this process. The closer to a window the antenna is, the stronger the signal should be.
7) If this does not work, you may have to install a roof top UHF/VHF antenna.
It really depends on how far you are from the TV station transmitters. In most cities TV stations build all their transmitters in the same general area.
When you get the antenna set up working call the cable company and cancel their service.
Now a couple of things to know. Everything is digital now. Wonderful picture IF you can get a signal, but digital signals don't travel as easily through walls and over hills and into valleys as analog did. You either will have a signal, or you won't. There is no fuzzy reception any more.
Can you tell I've walked a couple thousand people through this process in the past year? I do have to admit you make me feel old. I live in the last major U.S. city to be wired for cable TV...I was the first on my block to get cable back in 1987.