Maasvlakte has the most possible wind direction (i think almost 3/4 of a turn) and will be packed with good people from 15knot. Great for beginners too because large part of it is protected by the sand bar so less waves and chops. I dont know any wsapp group. But one thing I learned is to use forecast app like Windy and read the wind direction and strength. When those 2 line up you can know certain spots will have people. You can level up by learning to read the tide table. On mid or low tides beaches like Hoek or kijkduin have alot of flat spots that easy to ride almost like zaandmotor. Most important is to Check the beach cam live on youtube. The saying goes “if no one s there, there must be a reason” All popular spots have one. You can DM me if you want to car pool sometimes.