You’re joking, right? Most Irish people speak Gaelic. You hear it all the time when visiting. They speak it among themselves.
I looked it up. According to their census, 41% of people reported speaking Irish. However, there was no data about their level of proficiency or what language was used in their childhood home. If you’re learning Irish (or Cherokee) as a testament to your heritage, that’s very nice, but it’s not your “first language.”
Has their use of Gaelic affected their use of English? I ask because I used to have a job that occasionally required me to take customer calls from Canada. On a number of occasions I got calls from French speakers from Quebec and they couldn’t speak English to me. They also appeared not to understand me at all.