Could be many things, but I'd suggest the main reasons being:
I'd recomend getting a manual to check all of the above if you're not sure about how to check them!!
It is either getting no fuel or no spark.
Do a fuel pressure check. I had the same problem and it was my fuel pump.
check the distributor
It could possibly be the timing belt. Chevrolet recommends replacing it every 60,000 miles.
I had a similar problem turns out the Alternator was bad.
Obviously if it will not start, there IS something wrong with it.
dont no
Could be your starter.
turns over strong. might start and run for a couple of blocks but then dies.
Check for sparkCheck for fuel
wont, start,change punp,not getting gas
if all the other electronic parts work such as lights and and horn then it's probably a starter selinoid!