When cold, when I turn my car on it revs up and down from 0-1200rpm for about a minute then idles.

Pour a can of SeaFoam into the fuel tank, & get some throttle body-carb cleaner and spray it into the throttle body after you start the car up. To do that you need to remove the end of the air intake house from the TB end, and keep accelerating the car by hand while spraying into the throttle body. You should get a lot of smoke out of the exhaust pipe while doing this and possibly for a short time after while running it normally. You may also need to remove and clean the EGR valve from the engine and clean that as well with a wire brush(toothbrush type) and some TB cleaner as well. These cars are prone to carbon build up over time if not properly maintained and it is probably filthy with build up especially after not being driven for 3 years. Some fresh gas and some gas stabilizer in the tank certainly wouldn't hurt either.