It is customary for quests to bring a gift, like candy or flowers when invited to a meal in a French home. Also when engaging in dinner conversation, topics to avoid are asking about age, profession, salary, or political affiliation.
When you compliment a French person's home or possessions, the response will be the same as if you complimented their clothing or appearance. "C'est gentil", or "Vraiment?"
Also Notre-Dame de Chartes is one of the most famous Gothic cathedrals. It has most of its original stained-glass windows, famous for their rich colors.