I am relatively new to the arduino and robotc but I am trying to design a program that will be able to navigate any mazeusing just the ultrasonic sensor. I am hoping for the robot to go forwards until it reaches a wall where it will spin until it finds a new open path. I have no idea where to start though.

So the robot will probably move forward a bit, scan for obstacles, rinse and repeat. If an obstacle is detected then you probably want to rotate a bit, scan for obstacles, and so on. Does that sound like a plan?

You should use this Ultrasonic Sensor Library for Proteus and then simulate your project in Proteus first. Once you are satisfied then work on your real hardware. Its always best to design the simulation first. Moreover, have a look at these Embedded System Projects where they have given many projects in which they have interfaced ultrasonic sensor with arduino.