Agree with the above, ask questions, then make up your mind. First timers can be great guests, too.
I started hosting this summer, and have had 19 guests. Most have had reviews, but some have not, and this made me nervous, too. Especially if their initial message in the request to book was very short, not containing the info I was interested in. Some would just write ”Hi, I look forward to staying!”.
But I decided to give each guest a chance, by asking for more information before confirming/rejecting. I’ll write something like ”Thanks for your interest in my guest house. I see that you seem to be new to Airbnb/have not received any reviews yet. Therefore, could you please let me know a little about who’s coming (family, group of friends...?), and the reason for visiting Stockholm, so I can consider your request to book?”.
I realized that some of the guests just had not realized they were supposed to leave this kind of information, as during the booking process, they get an automated message from ”me”*, saying ”Hello! I’m looking forward to having you stay in my home. Please let me know when you expect to arrive. Trude.”
*) Message written by Aaurbnb and apparently cannot be changed (unless you have Instant Book, which I will never have).
In all but one case I have received more info and gotten a good feeling about the guest, and accepted the booking, and the guests have all been great!
There was only one guest that really didn’t feel ”right”, very reluctant or slow in giving the information I wanted, just kept saying they would drive from Norway to Sweden during the night (= 6-8 hours...), would be checking in the next day ”as agreed”, and that he/she would come back later with answers to my questions. Luckily, this guest had not made a firm booking request, only an ”enquiry”. And as I have a deadline for bookings (midnight day before), and he did not get back with information before the deadline, his enquiry automatically expired, so I did not have to reject any booking. I just promptly blocked the next night for bookings, sent him a polite message, and hoped that would be the last of it. It was.