UniFi NVR using non-UniFi cameras was a bit tough to set up, at least in a way that has ‘smart’ features. Presumably using UniFi cameras (and/or doorbell) would me much easier. But once running it’s easy to use, and there is a nice “Protect” app. Maybe check a how-to video for the app to take a look, unfortunately there is no demo site from Ubiquiti.