Hi Peter, I’m currently on holiday too, with even more time as I can’t sleep!
Your question’s been part answered in another thread here: Understanding the words in the introductory song
This contains a link to a YouTube video with lyrics in Welsh and English.
And if you want them written out so you can learn them word for word and impress your friends, try this link: https://www.gtleisure.co.uk/welshsongs/coffidu.htm
Happy holidays!