I forgot to include this sentence at the beginning.

1) I'm terribly sorry that I didn't manage to write you to you earlier. By the way, I hope it is not too late to send you all our best wishes for a year full of health and success.(our, I mean on behalf of our teaching staff and our school principal)
2) I'm pleased to read you have found accomodation at the hotel "....". By the way, how many from your and the French school will be there for the preliminary meeting?

1) I'm terribly sorry that I didn't manage to write you to you earlier. On behalf of our principal and teaching staff, we send you all our best wishes for a year full of health and success.

2) I'm pleased to read you have found accomodation at the Hotel Radisson. By the way, how many from your school and the French school will be there for the preliminary meeting?

To find the answer to the second question, you can start by checking the message or conversation thread where the previous information was discussed. Look for any mention of the French school or the preliminary meeting to see if a specific number of people attending was mentioned.

If you cannot find the information there, you can try contacting the person or organization mentioned in the message, in this case, the French school. You may reach out to them through email or another preferred mode of communication, and politely ask about the expected number of attendees from their school for the preliminary meeting at the hotel mentioned.

Remember to be clear and concise in your message and to express your gratitude for their assistance in providing the necessary information. It's always helpful to include your name, position, and any other relevant information to help them understand the context of your request.