There area few CL'c in this area if you are in the Caravan Club or Camping Club.I would suspect they may all be full, though, as camping is not allowed at the Steam Gathering. There's one at Grange, one at Allithwaite, a couple off the A590 near Haverthwaite and a little further afield there's a nice one at Ulverston.
Free camping, we haven't found anywhere immediately close although I don't suppose we have looked that closely, living in the area.
There is a campsite at Askam, about a 30 min drive from Cark. It has basic facilities but the field you camp in is just that, a field. Right next to the coast and golf course. It's only about £5 a night including hot water and showers!!