Some (probably dumb) questions re 4K discs

[nightcrawler]

Hi. So I am thinking about buying a 4K blu-ray player (multiregion), but have a few questions.
1) HDR - do ALL 4K discs have it, or is each release different?
2) Also on HDR - my only experience with HDR is with video games. In these you have to calibrate 2 different HDR settings, I think one is called “paper white” but can’t remember the other. Do these 2 settings also apply to 4K movies, and do you have to calibrate them for every single film?

Thanks.