If it cranks good, but, won't start, have helper crank it, while you visually check for spark at the spark plugs. If you have spark everywhere, use a gage and check fuel pressure. How long since a tune-up? Are there any applicable mil codes? You can check mil codes, yourself. Use a jumper wire between the A & B terminals at the datalink connector. Turn key just till dash lites come on, no further. The mil lamp on the dash starts flashing. You count the flashes to get the codes. Your looking for two digit codes.
To test for spark, you can use a spark tester. Plug it into the spark plug boot, ground metal part of tester to metal part of engine, engine cranking, watch for spark at the tester. The autostore sells a spark tester, doesn't cost much. There are other ways to check for spark, but, the tester is the safest, if you don't like getting bit by secondary ignition voltage, which I don't.