How Shift Register Works? page: https://goo.gl/GcZxCR

_31_arduSerie_sketch_02.74HC595.ino

const int clockPin = 9;             //Clock sequence
const int dataPin = 8;              //Serial data line
const int latchPin = 10;            //Latch Pin

void setup(){
  pinMode(clockPin, OUTPUT);
  pinMode(dataPin, OUTPUT);
  pinMode(latchPin, OUTPUT);
}

void loop(){
  for(int i = 0; i<8; i++)
  {
    shiftOut(dataPin, clockPin, MSBFIRST, B00000001 << i);
    digitalWrite(latchPin, HIGH);
    delay(200);//125*8 = 1 second
    digitalWrite(latchPin, LOW);
    
  }
  
  for (int j = 0; j<8; j++)
  {
    shiftOut(dataPin, clockPin, MSBFIRST, B10000000 >> j);
    digitalWrite(latchPin, HIGH);
    delay(200);//125*8 = 1 second
    digitalWrite(latchPin, LOW);
  }

}