Won't fire

Make sure battery has a full charge and connections all good. If it cranks good but won't start, have a helper crank it while you check for spark at the plugs. Use a gage and check proper fuel pressure and fuel injector pulse. Check for any applicable trouble codes. Those are the basic checks, in my opinion. You could use a test lite at fuses in your fuse box, to check for voltage, some fuses are hot all the time, some go hot with the key on, check em both ways. If your saying the starter motor won't crank the engine, we'll check the starter motor wiring circuits. Any testing make sure transmission is in park or neutral and parking brake is set. Just my opinion.