Dear friend,
I am glade(glade好像是这么写来着……）to hear that you went to America to study.And I know what you are worrying about,so I give you some advice to solve this problem.
First,you can join an English club to improve your English.It is helpful for your English.Then,you can get a part time job which place have a lot of people.So that you can hear them how to say English.The most important thing is that you should practice your English as much as you can.Do not be afraid of making mistakes,if you make mistakes ,you will remember your mistakes clearly and will not make them again.
I hope you can write to me soonand tell me the life in America.
Yours,
LILY