@Liz6
Since this is not going to get better by being nice, you will have to tell them to make the booking right now (best even while you are there) or they will have to vacate at once. Also contact Airbnb about this asap!!
If there are further problems, they are actually 'trespassing' at this point and you are in your right to contact the police.
Just make sure you inform all parties - guests + Airbnb - about the steps you plan to take!
https://community.airbnb.com/t5/Hosts/Contact-Airbnb-A-Community-Help-Guide/m-p/16165/highlight/fals...