Hi @Margo23!
You're going to discover very quickly that many guests send out inquiries to several hosts and don't follow-up with a booking. You can pre-approve multiple sets of guests (and you should). The first one to submit an actual reservation wins!
Since guests aren't always well informed about the system, whenever I pre-approve a guest, I always let them know a reservation is not considered confirmed until an actual reservation is made. I also tell inquiring guests that I often receive multiple inquiries fir the same dates, (I do!), and if they know they wish to book my space they should do so as quickly as possible to avoid being disappointed.
Jude