Answer:
Wiring a 2 wire fixture to 4 wire outlet depends on configuration of wires in outlet box.
If you have 2 white and 2 black I will assume there are more lights controlled by the same switch.
1st scenario attach both black wires to black of 120 volt fixture. Attach both white wires to white wire from fixture. atach ground to box or ground wire.
2nd scenario attach white neutral to white from fixture, Attach black hot to white going to switch. Attach black from switch to black from light Fixture.
If you need further help I recommend hiring a contractor. Take a look into contraxtor.com