If the engine will not even crank, it sounds as if you have an electrical power issue - such as a failed battery, failed charging system, or both. Have your battery tested first - is it low in charge? If so, have it recharged first and then checked for the capacity to handle a load. If it passes, then proceed with a charging system diagnosis. If it fails - replace the battery first, then proceed with the charging system diagnosis.
The alternator should be putting out upwards of 65 amps and 14 volts at 2,000 RPM of engine speed. Make sure the battery is good before having this tested. If the results fall below those amps and volts, then you likely have an alternator concern. Good luck.