When it comes to knowing English, not many people in Italy really know the language.
At the school, only Italian is used during lessons, even during lessons for complete beginners.
I must admit that at the school itself, the staff speak English with students who do not speak Italian well enough.
However, don't worry, I will always be available in case of any problems or doubts.
Age really doesn't make a difference, there are students of different age groups in the school and the groups are organized based on the level of Italian.
In your group you will probably find students of similar age, but also younger.