N53b25ul engine

Hi! I recently bought a BMW E60 523i. It's a one-owner car and has been serviced by BMW since new. When I bought the car, it had been without service for almost two years and had only been driven a few thousand kilometers since the original owner died and the car had changed hands to the grandson, who just kept it alive and running to sell it. Now I would really like to preserve it and keep it running since it has only 130,000 km on the clock and is in really good condition. Does anyone have any tips on what I can do for preventive maintenance? Or any other tips since this is my first N-engine.