I read this book when I was in fifth or fourth grade, and for the life of me I can't remember what it was called. It's about this Vietnamese kid, last name Nguyen, who comes to the US and lives with this family and becomes friends with their son (the main character). I'm certain that at first MC did not like sharing his house with the Vietnamese kid, but they grow to become friends. I remember the cover being an illustration of the main characters TP'ing a statue, almost certain it was in that "Apple Paperback cover" style that was widely used back then (see picture)
In fact, I'm certain it was an Apple Paperback book, but I couldn't find it searching through Apple Paperbacks. I'm certain the book was from the 90s, it had that sort of style and most of the books I read in fifth grade were from the 90s. It was at least post 70s as the Vietnam War had long since ended during the story.