It’s always recommended that you get something for your host family and the kids that you will looking after. Generally it’s something typical from your country. Most people bring candy because it’s the easiest and children always love candy.
When I came the first time, I went to the local market on the beach in my city to get something that is locally made and typically South African. I ended up with a salad spoon set for the host parents and I got my little girl a necklace and bracelet set. For my host boy, I got him books from the Dr Seuss collection that had wildlife and animals in. He really loved it because he loves books and that made him really happy.
You don’t have to bring anything big or expensive. Think about what you liked as a kid or what is typical to your country to help you have an idea as to what you should bring. I would recommend cookies or chocolate or even a game that is very typical to your country. If you know that your family is big into board games, it might be cool to get your local monopoly which seems to be everywhere. It might not be in English but everyone knows how to play monopoly so there should not be too many problems!
I know a lot of German Au Pairs would bring candy and chocolate because that’s always a good thing to bring. When I visited my family in England I brought stroop waffels and they loved it.
I hope this helps. Let us know down below if you have any ideas for gifts from when you came to America for your home country. I would love to hear from you.