Okay, so imagine you have a group of really popular people who always know what's cool and trendy. That's kind of what "tout-Paris" means. It's a term used in France to describe the most influential and connected people in Paris - the ones who are always in the know and who everyone wants to be friends with.
These people might be famous actors, models, musicians, writers, politicians, or just really rich and powerful business people. They often attend fancy parties and events together, and their opinions can have a big impact on what's popular or important in Parisian culture.
Basically, being part of tout-Paris means you're part of a special club of people who are really important and respected in the city. But just like any other exclusive club, it can be hard to get in if you're not already part of the inner circle.