Hello @Tara99. You need to quickly learn the lesson that hosts must never cancel whatever the reason (almost ;)). We get punished for doing so.
You could have used the option to block the dates while waiting for the first guest to book. But honestly, I am not in favour of using this option - some guests are picky, indecisive and would only spoil your business in that way.
View it this way: The first guest was shopping around and now is too late to book your place and "punished" for the indecesiveness. When you have Instant Book activated, it is first come, first served.
A host cancellation will hit you much, much harder than accepting a confirmed booking. Do a search on the matter in the help section or in the forum search window.