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To use the LCD you need to create the object in your code. If you connect it up like in the picture you need to create the instance like this:

LiquidCrystal lcd(23, 22, 16, 15, 14, 13);

To test if it works you can just run the example in Arduino IDE:

File → Example → LiquidCristal → HelloWorld

You need to change the “LiquidCrystal” instance in line 42.

/*   LiquidCrystal Library - Hello World
      Demonstrates the use a 16x2 LCD display.
      The LiquidCrystal  library works with all LCD displays that are compatible with the
      Hitachi HD44780 driver. There are many of them out there, and you  can usually tell them by the 16-pin interface.
      This sketch prints "Hello World!" to the LCD  and shows the time.
      Library originally added 18 Apr 2008  by David A. Mellis  library modified 5 Jul 2009  by Limor Fried (http://www.ladyada.net)  example added 9 Jul 2009  by Tom Igoe  modified 22 Nov 2010  by Tom Igoe
     This example code is in the public domain.  http://www.arduino.cc/en/Tutorial/LiquidCrystal  */

// include the library code:
#include <LiquidCrystal.h>
// initialize the library with the numbers of the interface pins
LiquidCrystal lcd(23, 22, 16, 15, 14, 13); void setup() {
// set up the LCD's number of columns and rows:
lcd.begin(16, 2);
// Print a message to the LCD.
lcd.print("hello, world!"); }

void loop() {
// set the cursor to column 0, line 1 // (note: line 1 is the second row, since counting begins with 0):
lcd.setCursor(0, 1);
// print the number of seconds since reset:
lcd.print(millis()/1000); }