Car has been sitting for three years

I would pull the plugs out. Spray a bit of fogging oil into each cylinder. Reinstall the plugs. Put in a known good battery. Check the oil level, coolant level and do a general inspection for rodent damage to the wiring.
Now hold the gas pedal to the floor (enables clear flood mode and should keep the injectors from dumping in fuel. Crank it over a couple times, does the oil light go out? If it does let off on the pedal and see if it starts. Run it until it warms up and change the oil/filter. Check it over close for hoses/belt damage, stuck or stiff parts. You will probably end up replacing the brakes unless it was stored indoors.

Once you get it running, top off the tank with gas.