You need a couple things to start a vechile.  Fuel, Spark, Air, and compression.  Check your spark.  take a plug and wire out while turing it over.  Lay the plug and wire on the side and have somone turn it over while you look to see if it's sparking.  Stand back to get shocked.  If you got spark and fuel make sure you have compression,  you can get a compression tester for a 15-20 dollars at an auto parts store.  They can give you the spec there too on how much compression if should have.  If you have compression most likely you timing is right.