Watch this while you bear in mind this is a dramatisation based on actual events. It's not a documentary. It requires some prior knowledge of occupation and of the horrors of WWII. It would be impossible to include everything that was going on at that time in one series.
Instead this focuses on the designers' stories. It's well made and compelling with immaculate production design and costume design, and excellent acting in a top notch drama series. If you want a factual account of life in occupied Paris, or of the lives Dior or Chanel, there are countless books on the subject. Grab a glass of wine and enjoying a great tv series.