Go by train directly from Amsterdam CS, it will take you only 30 minutes via Haarlem. Don't come by car on a hot summer day, because you're not the only one who wants to spend a day at sea. On nice summer days traffic jams around Zandvoort are huge as there are only two major routes leading to this village in the dunes. And parking space for cars is very rare and if available, very expensive!
5 km north of Zandvoort, you'll find another popular beach resort: Bloemendaal aan Zee. This is the more trendy area, which huge and chique beach clubs like Bloomingdale, De Kust and De Republiek. Here DJ's play all dag &night. This area is a bit more showing off, for both a straight and gay public.
From there it's another 15 minutes walk to the nudebeach area. You know when you have reached the gay part of the nude beach automatically....The gaybeach is at beachclub Eldorado. Clothing is optional!
At the end of a sunny day, the crowd moves back from Eldorado to beach club Havana, to have sunset dinner there.