Welcome to the group. i am not surprised that being of Cornish ancestry, and becoming involved with Cornish culture would lead you also to the Welsh, because of the very close links between the people and area.
It is good to know that someone is interested enough to keep some of it alive. I say some because so much must be lost. Cornish isn't considered a living language any longer. Well perhaps you would know more about that subject then I can possibly tell you.
My grandmother's family is from Cornwall originally too, a lot of moving around went on in the UK during the industrial revolution, and after the world wars, to the towns and cities.
But I know her ancestry back a few generations, and fortunately she recalls a great deal, and likes to talk.
They are from Salt Ash in Cornwall, and her grandfather was an armourer in the Royal Navy there. My grandad, yes the man she is married to is from Wales, well his parents were!
Many Cornish moved up to Wales to work in the mines, many are in the Rhondda Valley area. So when you hear about Welsh miners, think of all the Cornish! :)

There, I am storytelling. I think the Eisteddfod spirit has got me.
It would be great to hear about yours, and others ancestors.

Ylais
xxxx
ps excuse my welsh, and cornish grammar, spelling at the top, when it comes to writing it, I get a little confused., and speaking any Welsh too, but well Cornish, I only know a couple of words.