You can use the Location-based programming, where you input a zip code and it adds objects based on that location. You get a lot of objects added with this method that you probably don't want, and you'll likely want to rearrange objects that it adds.
Before you do that, you'll want to update the database included on the SD card. You'll need a computer to do this and the Whistler programming application.
Before long, you'll realize that it's worth taking the time to learn how to program it and create custom configurations for your particular listening interests.
Most Lexington County public safety radio traffic is on the Palmetto P25 system. It's all carried on the Lexington Co Simulcast site, so be sure that site is programmed. The radio only needs to control channel frequencies, not all of the site frequencies.
Depending on your location, you can probably monitor several sites, including those that carry Richland County and Columbia, Aiken Co and possibly Orangeburg Co.