how can i overcome the fear when i see foreigners that i can't talk with him?

First notebook entry: Introducing myself HI,friends.This is my firstime to get here,i feel a little bit nervous because of my poor Enlish words. i’m sunny and like to make friends,but i have Chinese traditional implicative character such as speak quitly. and others I‘m ambitious to learn English,but when i see foreigners i cant say any words.i dont know why,in my heart i have many topics and words to say,but i cant do it face to face.the reason i get here is that i want to improve my English. THX.