Regarding the NVR solution, I personally use both Frigate (Opensource, Free. Fantastic object detection, Really QUICK and accurate detections too), and Blue Iris (Closed source, requires 45$ license. But- amazingly powerful NVR software).

For cameras, I recommend POE cams. I Personally use reolink RLC-520s, and the likes. They support RTMP, RTSP, ONVIF, and will work with any NVR solution worth its salt. They are also quite cheap, and so far, have been pretty reliable. Of the 20 or so I have deployed, I have only had one die- which was due to it catching all of the rain coming off of the roof... in a storm. Warranty was honored on it.

Otherwise- as long as the camera supports one OF... RTSP, RTMP, ONVIF, you should be gold. For doorbell camera, Amcrest has a few options. I have an older AD110. They have newer offerings now. I do believe either reolink or amcrest also makes a POE powered doorbell camera, which would be good, if you have the ability to run POE to your doorbell.

EmpireTech T5442T-ZE (rebranded Dahua) is a fantastic outdoor camera. Significantly better image quality than any Reolink, especially at night. Any camera that supports ONVIF will work well. Avoid any that don't use ONVIF and require you to use their app.

I use Blue Iris as my NVR, but Frigate is decent too. Frigate has way fewer features though, and to get good AI detection models you have to pay a monthly fee, so you may as well pay for Blue Iris and get a significantly better software package.

You... want a what?

If you want to just control scenes, hardware-agnostic, just try home assistant.