Honestly, just download/install from your package manager and then start using it. One of the best built-in modes is called Org mode. Don't try anything crazy because it's easy to get overwhelmed. It took me some periods of stopping and starting before things felt natural and became my daily driver.

How do you think one should get started with Emacs? Should they start start with regular GNU Emacs or should they install one of the “distros”?

I always recommend using the default setup for any software. The same goes for learning GIMP, Krita, Blender, FreeCAD, or whatever else, even though you can customize them all to your liking.

It is usually a good idea to try and learn the workflow that was intended by the people who developed this software, you could learn something from trying to use the computer in the same way that the professionals do. Same for Emacs: professional software developers have used it for almost 50 years, the default keyboard shortcuts are set the way they are partially for random historical reasons, but partially because they often make a lot of sense.

If you are interested, please check out my blog series on getting started with Emacs, called Emacs for Professionals