4 years stored, WOW good luck....
Gasoline is bad for sure, injectors need cleaning aswell, hopefully it was stored dry, no fluids, you could have worn and or cracking seals. Where ever the fluids sat in contact with rubber you could have trouble...Hopefully it was lifted or you probably have warped tires, suspension issues, etc.. 4 years is a long time for a car to sit, hope you got it cheap...
I would first start by changing "all" the fluids and belts...Included tranny fluid...Extract the gasoline and put new 91 octane...Change spark plugs, check for leaks under the car, change all filters, air, fuel.... Clean throttle body, check battery, cap and rotor, etc...See if the car will hold an idle after all that... That's what I would do first....