There isn't an official list of essentials... It depends completely in your lifestyle and figure and personal preference. The "typical" French items are often claimed to be the Breton, ballerinas, trench and beret. I wouldn't even claim that leather boots are essential to a "french" wardrobe. None of the items mentioned are essential, really.
You can find several fun lists online, though.
Essentials List:
Something to cover your body
Something to keep you warm
Something to protect your feet
Something to keep your stuff in
You'll have to narrow it down depending on your lifestyle, figure and taste