3white wires and one black from the ceiling. How do I wire up a two wire fixture?
The black and white wires which have wire-nuts go to the new lamp fixture.  

You will be sacrificing 0-10V dimming, emergency lighting, or whatever purpose those other two white wires have.   Note that they are a "line cord" which has been split; this is an illegal wiring method for mains power in a building's structure, hence my suspicion that they are for low voltage.  

Also, you should rearrange this so you are wiring into a proper junction box, and if there already is a box, ad a box extension.  This may involve re-positioning the new light slightly.