If you want to monitor public service agencies, you'll need a digital unit. Horry County and the incorporated municipalities within switched to a P25 phase I digital voice system several weeks ago. The SC Highway Patrol will also switch to digital over the next few months. See https://www.radioreference.com/apps/db/?sid=9279 for more info.
You may be able to monitor Horry County Fire Rescue on VHF…but that too will probably disappear in the coming months.