Cornwall is a big place! where in Cornwall were you hoping to find sessions? North, Middle or south?
In North Cornwall you could pm me and we could arrange something, I have several folkie friends who are keen to sesh at any time! Also contact Hobgoblin at Wadebridge, the chap there may be able to enlighten you
Further down, contact local folk club leaders, who usually know whats happening in their neck of the woods. See Folknews Kernow on google for Folk Clubs and they should have contact numbers of people who know whats on in their locality.
Hope that helps
Cheers, Lucy