@Mimi226
I'm seeing red flags here just from instinct, because of 0 reviews.
May I suggest that you....
1st - Contact Airbnb and have a "note" put on the reservation that the guest is not responding to communications (and also notify them of your next step below)
2nd - Message your guest that since he is not responding that you may have to cancel his reservation due to lack of communication.
In my thought process...
1 - You are alerting Airbnb
2 - You are being proactive
3 - You are building your case if something is not above board
4 - Your guest has effectively been "warned/notified.