Hello.Limin! I am glad to hear that you have studied in a new senior middle school in your letter.I am sorry to hear that you are not getting along well with your new life in school. Now I want to give you some advice. First you should be self-confident and you should be dressed properly, which can make a good impression on others.Second you should be honest and keep your promise .Third you should always smile to others ,which can show you are friendly.In that case your classmates would like to make friends with you.Finally you should take part in activities as much as you can to train yourself and you can also learn a lot in them.I think only in this way can you adapted yourself to the new life in the new school.