Welcome to the hobby. As with all communication technology, radio technology has advanced significantly in the last 2 decades or so. And that applies to public safety communications also. In the Charlotte area, almost all local public safety communications (assuming that's what you're interested in listening to) is on a digital trunked radio system. State agencies mostly use a different but similar radio system. You'll probably need the most expensive scanner available today to be able to monitor the County system reliably. There are other less expensive non-scanner options for listening.
And there are other things to listen to - businesses, colleges and schools, aircraft, amateur radio, utilities. Some of these monitoring targets use different forms of digital radio systems. My advice is to decide what it is you're most interested in listening to, researching the type of radio system(s) those targets use, and then research a monitoring device/platform that suits your preferences. Doing this in opposite order (purchasing a device, researching, and then deciding what you're able to listen to) often leads to disappointment.
There is a ton of information on this site, and lots of willing folks to answer specific questions you may have. Good luck.
