New box - when to expect visits?

Hi John, so pleased you’ve an early visit.  When you have two checking out the box it is usually a male and female pair.  Most often the male does the seeking for a new box and then brings the female to approve or otherwise of his choice (a bit like the human world actually ha ha).  You will find that if he manages to get the female to enter, he is often then chased out whilst she does her own inspection .  Once the decision for a box has been made it will be (in most cases) the female alone that builds the nest and the male only comes into his own when she requires him for the fertilising of her eggs.  I can never tell the male and female apart except for their behaviour once in the box.  This is a great start for you so everything crossed 
Sue