I've ridden on Amtrak trains. The door for the passenger compartments is in the middle of the observation cars, the oval on the lower level is the window on the door. You can see 3 of them on the 3 cars. The crew would put out a step at stops which was helpful considering the age of most of the passengers.

Up top are seats and maybe a lounge, below are bedrooms, bathrooms, and storage. There's a spiral staircase to change levels.

The locomotive has steps right outside the wheels with handrails.

I'm not sure I follow what you're trying to say.

It's pretty obvious where the doors are (middle), which have windows. My point, replying to my parent, was that they said Amtrak platforms are at 110cm height. The lowest part of those doors are not at 110cm height, but much lower, almost as if the platform was much much lower than my parent claimed ;)

And yes, trains do exist, which either have doors at two different heights (these don't seem to) or that either automatically fold away so you can get out at ground level via the stairs that are revealed/created by the mechanism or that simply stay up for platform height entry/exit. Used both types. Now, whether or not Amtrak has those in specific parts of the US I can't say.