engines are pretty simple.. you just need fuel, spark and some air and at least something will happen.

pull a spark plug out and smell inside the chamber after you try to crank the car for a bit.. does it smell like fuel? if so, then you have a spark problem. the plugs may be fouled enough that they wont spark.

timing is most likely a non issue, no junk yard would take a motor apart and reassemble it before selling it..