What cultural faux pas should I try to avoid making in Nantes?

"When visiting Nantes, it's important to remember that the French value their language and may take offense if you don't at least attempt to speak some basic French phrases. Even if your French is not perfect, they will appreciate your effort. Avoid being too loud or boisterous in public places. The French tend to be more reserved and may view loud behavior as disrespectful. In France, it's customary to greet people with a kiss on both cheeks. However, this is usually reserved for people who know each other well. If you're meeting someone for the first time, a handshake is more appropriate. When dining out, remember that the French take their food very seriously. Avoid asking for substitutions or changes to the menu, as this can be seen as an insult to the chef. It's also important to remember that tipping is not as common in France as it is in other countries. Service charge is usually included in the bill, so additional tipping is not necessary unless you received exceptional service. In Nantes, as in the rest of France, it's considered rude to interrupt someone while they're speaking. Wait for the other person to finish their thought before you start speaking. Finally, avoid discussing sensitive topics such as politics or religion unless you know the person well. The French value their privacy and may not appreciate being asked personal questions by strangers," said another expat in Nantes, France.