Ravenstonedale is a lovely Cumbrian village in the Howgill fells, and the Black Swan is a great pub which serves some very good food but I don't think there is any folk club or session in the village. Check Cumbria Folk News for information; I think there used to be a session in Kirkby Stephen, and there may be something going on in Sedbergh. There are occasional singing workshops at Farfield Mill, and in fact if you are around on Feb 28/29 there is an all day Harmony workshop (cost £15) on the Saturday, and a concert at Dent Memorial Hall on the Sunday. See Events Calendar.
Enjoy your holiday there; it is a beautiful part of the world.