Being on vacation in a foreign country can be very shocking because of all the cultural differences. They maybe greet each other way differently than you're used to.
Well moving to a completely new country, there are even more cultural differences you'll have to adapt to fit in. Knowing how to act in different cultures is not a necessity, every culture has their norms.
The narrator which is a first-person narrator is a Chinese girl. She very much tries to be American, she is scared to make any mistakes while talking "I worried more about making mistakes, and I spoke carefully
making sure I could say everything right before opening my mouth."(s.4 l.1). The narrator appears very insecure and she is embarrassed by how her family is behaving.