does not implement interface member

Your class GetVenues does not implement the method mentioned in your error message. Where exactly are you stuck? GetVenuesByLocation(string search) is defined in the class Venue.

I have noticed that this question is starting to garner interest. The issue here is very easy: your class does not implement (even if it’s abstract, you have to define them) all methods defined in the interface. Your IDE should warn you of this before compiling.