How can I configure one pin for input and another for the output?
If I am not wrong this could be done with GPIO registers that controlls device pins that are not connected to peripherical functions.
Look in UM10360.PDF, Chapter 9: GPIO. There you can find the description for the FIOxDIR direction registers, as well as the reigisters for querying, setting and clearing GPIO pins.
I also strongly recommend looking at the CMSIS Standard Peripherial Driver Library that NXP offers for 175x/176x, look in microcontroller support documents. Edit: There are lots of sample code in this Library.