If you don't have IB turned on, no-one should be able to book without you approving it.
If a booking has been made that you didn't approve, call Airbnb straight away and ask them to cancel the booking.
I have it as part of my booking conditions for IB that only guests with clear photos who tell me about why they are visiting my area and why they chose my place can book.
Not having a photo or profile information is not necessarily a bad thing, for some strange reason Airbnb has changed it so it is no longer mandatory to have a photo so some new guests don't,
Review your listing to put security measures in place that make you comfortable.