Need help creating a sketch for arduino

Create a Sketch for Arduino board to use the 6 LEDs ( 2 green ones, 2 yellow ones, and 2 red ones) to create a prototype of traffic lighting for an intersection, with a breadboard and wires to build the circuit. One set of green, yellow, and red LEDs control the traffic along one direction (say Apple Ave), while the other set control the other direction (say Peach St). The working procedure is below: In the beginning, the green light is on for Apple Ave, while red light is on for Peach St; After 10 seconds, the green light changes to Apple Ave, and yellow light is on, while Peach St still has the red light; After 2 seconds, the yellow light is off on Apple Ave, and red light is turned on. Peach St. has the green light; Repeat (1) to (3) but switch Apple Ave with Peach St, back and forth