@Stephanie2174 18 years old is the age at which a person can open an Airbnb account and book. We are not supposed to practice age discrimination, but of course 18-19 year olds booking is a source of concern for hosts. If you are in an HOA or something that prohibits those under a certain age from staying there, you would need to mention that in your ad and could have an age restriction.
Otherwise you will just need to vet guests carefully, make sure they are aware of the house rules, check-out instructions ( the host is not your mommy- you need to wash your dirty dishes, and tidy up your messes before leaving, stated tactfully, of course) and coonsequences for ignoring house rules. Question them about their reason for wanting to book with you, their intentions during their stay. If they have incomplete profiles andd no verified ID, ask them to submit that to Airbnb.
Whether they drink or not is really none of your concern. I'm not sure where you got the idea that you would be held responsible. Unless they are staying in your home where you live or you have provided the liquor, it's not your responsilibity. There are plenty of people that age who drink responsibly and plenty of people much older who don't. Your concerns should just be that they treat your place respectfully.
There are some things you might want to make quite clear, as folks that age just don't generally have enough life experience to know how to deal with things. For instance, let them know that should anything get accidentally damaged or broken or isn't functioning properly, that guests are supposed to let the host know right away, not try to "fix" it themselves, which could result in making it worse. You don't want them scrubbing something they spilled on a carpet with bleach so they won't "get in trouble".
