New - Help pick device for my use case please

Totally new to this and a bit overwhelemed with all the options. From my searching it looks like the gmc-320+, gmc-600+, or Radicode 103 may be a good option but I am not sure.

Use cases would be, seeing if something is radioactive, detect radon, measure how much dose per hour I am being radiated with, measure for a period of time (useful for radon detection).

It would be sort of neat to just see what is radioactive around me and to measure things. And to know if something was contaminated say from nuke going off or contamination from industrial stuff and what not and to know if something was safe to eat for the few days I may survive nuclear armageddon lol.