Hi Lesley,
Yes - I work part of the year in Holland, and often take a weekend break in Belgium.
So - which UK ferry port will you use? I'd suggest looking first at Norfolk Lines (Dover - Dunkerque) or P&O (if you have Tesco points). Or if you can travel mid-week and at odd-times, then the Harwich - Rotterdam Europoort service often has "caravan goes free" offers.
I know the coastal regions quite well, and for the Brugge (Bruges) to Gent, I've recommended both Camping Memling and Camping Blaarmeersen
On the both banks of the Scheldte river, roughly on the border between Belgium and Holland - there are loads of good quality camp-sites.
Then in Holland, Delftsehout (Delft) is good and very convenient for visiting the "Golden Age" cities of Holland (Amsterdam, Leiden, Delft, etc)
Language - English is widely spoken in Holland and in the Dutch speaking-region of Belgium.
And we've just returned from along weekend in Damme - about 5 km north east of Brugge - just fantastic - first rate food, great beer, good shopping and a fantastic time.
Robert