@Myriam4 Hi Myriam....Firstly, is this guest a confirmed booking?...does he show up in your reservations? Obviously you are corresponding through the Airbnb message stream which tends to indicate the booking has been accepted and if that is the case all you need to do is welcome your guest when he arrives.
If you want further clarification contact Airbnb direct. This is a forum site and we do not represent Airbnb, we just use them.
You do not list what country you are from but, your listing appears to be in Rio in Brazil! The phone number for Brazil is ....
Brazil+55 21 3958-5800
Please take a note of that phone number Myriam for future reference. The delays you may experience in getting through to someone personally will vary from country to country. In Australia the delay is very rarely more than a couple of minutes! In the United States the delay, at times, can be substantial, I can't tell you what it will be like in Brazil…..but remember, help is at hand, all you have to do is ask for it!....Cheers….Rob