yeah, there's a couple of gaelic languages spoken, irish, scots and manx which are goidelic, and welsh, breton and cornish which are brythonic. the only ones that are spoken to any real degree are irish, welsh and breton.
If you rank according to the number of speakers:
1) Welsh (700k +)
2) Breton (210k +)
3) Irish (native to 90k +, but many ppl in Ireland understand it)
4) Scottish (native to 50k +, some ppl in Scotland understand it)
5) Cornish (about 300 ppl speak it)
6) Manx (extinxt as a first language)
I think it would make sense to learn Welsh? There is even a course on duolingo. Gaelic languages are really un-appreciated.