When someone calls for care .... Generally they say they are looking for care for their child and generally they give you the age! But the questions I ask are
How old is the child?
When do you need care to commence ?
What hours are you requiring? (drop off and pick up)
I let them know its a full time spot (I dont do part time)
If they don't ask my rate I tell them and I also charge per day and not by the hour
I ask if the child has allergies?
I let them know I have a dog (even though its in all my ads )
If this is an older child I ask if they have been in care before? Why they left?
Generally they ask a few questions
I don't lower my rates , I don't offer a sibling discount, I don't travel with my kids,
Then if they are interested they will usually ask when they can book an appt . I do mine evenings and weekends not during daycare hours.

Hope this helps