The story of Arrival is about a husband of a family in an old country full of "dragons", who comes to the New World first to settle down for the family to move. From the details in the book, all those weird creatures, strange-looking food and the gap of languages, we could see the bewilderness of the first generation immigrants.
But all the aliens will at last come to a point when they become the "local resident". That's the time when they find out there can be more than one home. As the last page the daughter shows a new immigrant the way, we could see the self-identification as a citizen of New World.
This is the tale of all those who come to an alien place for a brighter future.