@Helen924
You posting is confusing, as an enquiry is not the same as a booking request
It seems you mention "enquiry" where it is a booking request (an enquiry can not be withdrawn.)
So the guest must sent you an enquiry (by clicking in your listing on the link "contact the host").
Reply to the guest you will sent a special offer.
Then click on the button "special offer", create the offer and sent it to the guest. Then the guest has 24 hours to accept the offer (but should act quick, as somebody else can book as dates are not reserved until offer is accepted).