We were taught nothing. Our history lessons barely touched on the 20th century or even the 19th century.
I entered secondary school at the age of 11, in 1957, meaning that WW2 was very recent history, 12 years being the mere blink of an eye. More amazingly still, we were taught nothing of The Great War 1914-1918, the single event that transformed Europe.
Everything I know has been self taught. A French person might know more about the Vichy govt.
As far as I can see the Vichy govt. was a pure puppet of Germany and had zero credibility or independent decision making power.
The role of the Maginot line is covered in the book. It did nothing to stop the German attack as they never made a direct assault on it apart from one unsuccessful assault at the northern end of the line. No further efforts were needed as the French army was defeated in other parts of the country resulting in surrender.