If you are coming to Rotterdam The Hague Airport to pick someone up or to drop someone off, this is very easily done.
There are Kiss & Ride lanes located near the airport terminal building. These can be used by all drivers who are dropping off or picking up. These can be clearly seen on the map below. Of course, there are also sign boards on the airport grounds which show clearly where the Kiss & Ride lanes are, and how to reach them.
If you wish to stay longer at the airport, you can park on car park P2 in front of the terminal. If you only want to pick up or drop off, you can do this on the Kiss & Ride. The map below clearly shows where this is, and of course, at the airport you will see signs clearly showing these locations.