What power adapter should I use in France?

I will bring my iPad and my iPod nano 7th generation, and my iPhone 6 Plus to Europe from America. I only have 2 of the 5 watts adapter, and 1 of the 12 watts. I am planning to buy the World Travel Adapter Kit, I am going from Massachusetts to France and the rest of Europe. What power adapter should I use out of the 5 watt, 12 watt, or the world travel adapter kit, or the 30 pin or lightning?