@BichonBistro Oh my, you probably shouldn't use my illustrations for this exercise ^^''''' I frequently cheat with perspective. Even when I don't, since my vanishing points are usually way outside my canvas I usually approximate where they should be and draw a self-made grid by eyeing it, not by actually following the line all the way to the vanishing point - then I draw my perspective to follow the grid I just drew. I can get away with this because I'm very familiar with perspective and my style is cartoony enough to allow for a reasonable margin of error.
But as a matter of fact this illustration was based on a loose 2 points perspective grid, not 1 point.

This is the gird I used. The yellow lines will converge into one point on the outside of the canvas (sort of, again I was eyeing it) and the red lines will converge to the other point.
I think you did a good job identifying the perspective in the last photo. The folder and paper pad that have a different VP are crooked and angled differently so they don't count. As for the Paddington image, it's loosely based on a 1 point perspective but it's hand-drawn and doesn't follow it closely. You could call it mistakes, or style, depending on your point of view on the matter. You shouldn't use illustrations for this exercise because there's always the chance that they have tweaked the perspective or aren't following it much at all.
The first photo is not a 1 point perspective, it is 2 points. You have correctly identified one of them, but there is another on the left side of the canvas. In a one point perspective, you will always see one side of the objects/buildings fully from the front. If you see a corner and both sides of the object are angled, what you have is a 2 points perspective, not 1 point.
I would advise to refrain from looking for exercises images by yourself... You have picked illustrations that both largely cheat on perspective, which is understandably confusing you further. Photos are better for exercise, but you have picked one that is a 2 points perspective, again confusing you even more. If you must look for exercise photos, look with specific search terms like "1 point perspective example" to make sure you get a correct one. Good luck hun!