You don't find any moped riders in Paris or its surrounding.
Mopeds are long gone in the capital, replaced by scooter and 50cc 6 speeds trendier and more reliable if you're 14 years old with no motorcycle license yet.
You find more mopeds in the country side or close to big cities in the south because some kids don't have the budget to buy a scooter and don't have as many options. They tend to be a little behind the capital trends.
We're also starting to see older nostalgic guys rebuilding mopeds in the country.
But mopeds are not really a culture or a movement like they are in America.