Arduinakias,
Have you read the "How to use this forum" at the top of the page?
Depending on which version of Arduino you are using (1.0.3 up) there are examples included for using I2C LCDs.
Do you have the datasheet for the display, what is it's address, link to the retailers page/examples?
It is very easy to program once you get some basic parameters right, I think it is called a constructor, that has to be initialized at the start of the sketch.
If you have an older version of Arduino, search here for NewLiquidCrystal to find the new library for LCDs, with lots of help for installing and using.
You will also need the relevant library for the RTC.
You also might try searching the playground for more examples.
Google is your friend, lots of tutorials out there.
TomJ