The database that comes with the BCD536 are probably from 2016. You will have to download the latest database from Uniden to be updated and then do the zip code selection. But if you live where there are few people using scanners, then it might be several systems that are not in the database as no one have reported anything to RR. The database are depending on that people with scanners are reporting their findings to RadioReference that then Uniden uses to create their own database.
If there's not much to monitor even after you update the database then you'll have to do frequency searches to find what's out there. You can program 10 search ranges in the scanner and I suggest to set the delay for each one to -10 sec, negative 10 sec, and start the recorder. It will then stop on active frequencies and save the audio and after 10 sec it will continue to scan. If you notice that it stops on the same frequency several times without any conversations are heard you can do Avoid to that frequency.
Let it do searches for a full week whenever you are not actively listening. When done you can install the Universal Audio Player by deim here in the RR forum and copy the audio folders from the scanners SD card, there's 100 recordings in each folder, and put in the same directory as the audio player and have it show the info from the channel and also listen to the audio. Then collect all info and program the scanner with any new info you have discovered.
/Ubbe