You can probably find a visual walkthrough of the GUI by searching youtube.
There's a login page. After you authenticate, there's a live view page, a review/recordings page if you are recording to SD card in camera, and a few settings pages.
I'd say you could absolutely access the camera standalone, but at least the cameras I have don't do any detection or notifications. That's where the NVR comes in. I know reolink has cameras that do all of the above including AI detection.
I was in your position recently and decided to install PVE from scratch and restore VMs from backup.
I had a fairly complex PVE config so it took some additional work to get everything up and running. But it was absolutely worth it.