You program them into your scanner along with the frequencies. Program the "DEC" talk groups, not the "HEX". On a trunked system, units transmit and receive on talk groups. When a specific unit transmits or the dispatcher wants to talk to that unit, the talk group ID will appear on the screen of your scanner.
Each troop (A, B. C)has more than one communications dispatch sector. 2COM through 5 COM. Turnpike (Troop D) and Parkway (Troop E) have 1 COM through 3 COM. Take a look at the database here for appropriate talk groups for each. Depending on where you live, you will be able to receive (probably) receive two of the three regional troops closest to you plus turnpike and parkway.