Rabia,
It would be handy if you could give some more info on the example you used, because it could be that it is doing all it's supposed to do (there are some examples that just generate a test pattern to test the outputs).
You can always check in the SOPC builder of the project what the main configuration is. It's also there that you can change the resolution etc.
On the following website you can watch some free online training courses which should help you get started with the Quartus II software:
http://www.altera.com/education/training/curriculum/fpga/trn-fpga.html Anymore questions, ask them, I'll try to help (for I am not a specialist myself...;) )
Best,
Hans