firstly, is the wifi shield able to communicate with the Arduino
Yes, but the communication is handled entirely by the Arduino.
how would i go about sending the information to the wifi shield (directions etc.) over wifi so that the shield will tell the Arduino what to do.
The shield doesn't tell the Arduino what to do. The Arduino asks the shield if any connections have been made, that might be defining what it needs to do.
The Arduino with WiFi shield needs to be a server, responding to GET requests.