You don't say how log you are planning to go (65 so retired?).
Camping in NL is easy and cycling is great.
One route I'd recommend subject to how long you are going for would be
LF Waterlinieroute. It's an established NL Cycling long distance route (signposted all the way) it Nederland Fietsland established route (
https://www.nederlandfietsland.nl/fietsroute/lf-waterlinieroute/).
In english Dutch Waterline. It's a historic defensive line constructed for the defence of Holland (Holland rather than Netherlands) and it's a UNESCO World Heritage Site (though a fairly long one!. It's flat low lying land running from mid west side of IJsselmeer (Edam) south to Bergen Op Zoom area. The idea was that when faced with invading troops dykes and sluices would be opened to flood a large flat area to a depth of a few feet making it too deep to march through but too shallow for boats.
Along the "line" are a number of different forts and water management features of varying ages (WW2 and older). Forts are interesting, some abandoned, some being renovated, some now commercial cafe's, etc. I even camped at one (you camp inside the fort compound.
Overall 255 miles (though you could start midway and just do part).
Easiest way to sort camping (that I found) is to use
https://cycle.travel/map/journey/268630 and press the "Find Hotels and Campsites" button then top left of the map uncheck hotels and chains.
Fairly convenient for Hoek ferry post. Do ask if any details if you are potentially interested.