Proofreading?

Hi Teachers, Please help correct my letter if there are any grammatical mistakes. Thank you very much!

Dear Sir/Madam,

I’m the chairman of the students’ union and I am writing on behalf of our school to inform you that there will be a school trip next Sunday.
There are several things as follows I need to have your attention:
As you all know, senior students in our school are going to take the entrance examination of college in the coming year. Many of them said they want to study abroad and they recommended arranging a short term study tour in the winter holiday. Accordingly, we are planning to go to London for a week.

All the students are divided into 5 groups, and 5 students and a guide teacher are in a group. Students will be put up in a student dormitory where there is a particular person has been put in charge of daily life. So, you don’t need to worry about your children.
During the trip, students are arranged to take some language courses in local famous universities, and they will visit some tourist attractions as well.

Last but no least, the most important thing is that be sure to bring passport, ID cars, student ID card with your children. And don’t carry much cash on them.

Thank you.

Yours sincerely,
Mary.