Vancouver immigrants landed.

In Vancouver, you don't need to submit any documents if you don't enter Canada (of course, you may check your passport before boarding a plane in Vancouver for the United States, but it's not other documents, so don't be nervous. )

All the official entry formalities are handled after landing in the United States, where the big envelope of the embassy is handed in. In addition, the airport staff will ask you to fill out some forms (very simple) to help you apply for a green card. After filling it out, you will receive your official green card in about a month (but not necessarily the green card of the whole family). Take it easy. Many new immigrants arrive in America every day, and you will get along well.

Have a nice trip!