Whether a student or avid traveler, staying with a host family can be an amazing experience with first hand exposure to the culture, language, and food. But, of course there are fears and worries about staying with a family you have never meet, and the host family has them too about letting a stranger into their home. You want this time that you are staying with them to be enjoyable, full of intercultural learning and exchanges.
Firstly and most importantly, remember to be gracious no matter the circumstances. This family has opened their home up to you, willingly. You may feel like family, but you are still a guest. Offer to help with preparing the meals, to set the table, to do your own laundry, to take the trash out.
Don't worry about offending your new family by not following cultural norms the first time you meet them. Usually, they will be understanding about your lack of knowledge and be very helpful in pointing out where you went wrong. And by the time you leave, you will all be laughing about the first times you attempted to fit in! By all means though, look up these norms before you leave home. You can impress your family by showing that you are already familiar with their customs. (Bonus Points for being the best adopted family member!)
Ask lots of questions. They are bound to forget to tell you something like when dinner is or that to turn on the light you have to pull down the string at the same time as flicking the light switch on. These things are part of their daily life, they don't think about it. However, you could be quite lost in the dark or very hungry, if you don't ask.
But don't ask just these "logistical" questions. Inquire into why they have a particular custom, who are popular artists, what do people do for fun, what is this word in your language. People love to talk about what they know best! Plus, it makes for an engaging conversation comparing lives. You could even tell them about what is popular or not back home. They will want to learn about your home and culture, too!
Take one night to repay their graciousness and do something for them. It is fun to cook them a popular American dinner. Whether you are culinary master or can't even boil water, they will be so thankful that you at least tried. And who knows they might want to help you make the dinner and exchange recipes!!
At the end of the stay or even during your stay, don't be surprised if they want to show you off to their friends and family. You have spent some (more like a lot) time with them, and you feel like family! This would be the perfect time to show the traditions or new words and phrases you learned in the language during your visit. Make their guest want to host visitors, too!
And don't forget to stay in touch with your new-found family and friends! With all the social media we have now a days, it is easier than ever to do so. Who knows the next time you visit, they may welcome you back. Or even better they may come visit you!