@Ursula9 It looks like the guest put through a cancellation. Possibly at your request? When a guest cancels Airbnb does not refund their service fees. That's why the guest was refunded all but the $71.
What are your options? You can try to ask Airbnb to refund the service fees but I doubt they will do it. Or, you can send a refund request through the Resolution Center in which case the $71 will come out of your pocket. That's the equitable solution since it appears that you were the one that could not accomodate the guest. Here are some links to assist you:
https://community.airbnb.com/t5/Tips-Tricks/Contact-Airbnb-A-Community-Help-Guide/m-p/16165/highligh...
https://community.airbnb.com/t5/General-Hosting/The-Resolution-Center-A-Community-Help-Guide-Request...
Since you are new and don't quite understand how Airbnb works, I would strongly urge you to turn off Instant Book. Also, you should shorten your calendar availability so you are not receiving reservation requests so far off in the future. You can do this by going to your Availability Settings to the right of your Calendar in Manage Listing. You can shorten the time period to 3, 6 or 12 months for receiving guests.
Hope this helps!