Method to Use to Get live Flight Status Updates

What method should be used to get flight status updates from 24hrs-departure for only one flight. The flight number is an input and I need to get the scheduled departure time and estimated departure time. I am unsure how to do this any help is appreciated.

Just use FlightInfoEx for the ident you want, and look through the results for the specific instance of the flight you are interested in. You should not attempt to specify howMany=1, since that will only return a single flight and likely not the instance you are looking for. (The API cost is the same for <= 15 results from that function, so do not be worried about the overhead of the extra results returned.)