The first program you should ever write is a hello world. In that you will see it say
print("hello world")
That is what a print statement is.
Having said that then I do think you should learn something about what you are trying to do first without trying something several miles over your head.
You should tell us what is and what is not working.
Do you see the changes in the graphics in the processing app?
Do you see the RX LED blinking on the Arduino?