In terms of software: Agent NVR is imho currently one of the easiest and most compatible camera software systems available for free. Runs on a pi,even though I would absolutely not recommend one

(Use a proper x64 SBC like the zimaboard. Makes a lot of things easier).

Camera wise Dahua, Hikvison and Foscam are far better than Reolink, imho, but they most definitely need a separate network or a block so they don’t access the internet.