98 Chevy Silverado 5.7 4x4 will turn over but will not start

First need to check and see if there is spark. If there is then something with the ignition system. If that is ok then a fuel pressure test and fuel bleed down test would need to be done. May have leaking fuel injector assembly or a bad fuel pump. Fuel pressure should be 56 to 63 lbs.

Without going somewhere to get that done how can I do it myself

Take the coil wire off and put it by ground with a slight air gap. Insulate your hands or use something plastic to hang onto the wire. Sometimes you can just get it to lay there. Have someone turn the engine over and watch for spark. It should be white, blues in color, not orange. Fuel pressure you would need a fuel pressure gauge to hook up to the Schrader Valve. Turn the key on to build up fuel pressure on the gauge. Take note of what it is. Should be 56 to 63 lbs. Then turn the key off and watch the pressure gauge. Fuel pressure should not drop more than 5 lbs. in 3 minutes.

always set your # 1 piston on top dead center before doing any distributer or plug wire replacment

Look at ur thermostat sensor..if it's unplugged that's ur issue....I have a 98 k1500 4×4 and it started overheating not wanting to start and dying when it came to shifting it into gear....come to find out the thermostat temperature sensor wasn't plugged it at all that regulates all the pressure sensors etc...after I replaced it truck runs like it was brand new!!!