My known Irish surnames are BAILEY, BUCHANAN, DOAK, DONOHOE, FERRELL, FLEMING, LEWIS, MITCHELL, MOORE, MURPHY, and SELLARDS, possibly others. Most of them immigrated to the USA before 1800.
Hi TM, looking at old queries and interesting names, surprised to see the list does not include any counties in what is now Northern Ireland. Some rare names there and some common, rare to me is Sellards, also Doak, McLysaghts Surnames of Ireland says along with Doag it is a variant of t. he Scottish Davock. Ferrell is a variant of Farrell I imagine. Buchanan is Scottish and probably Northern Ireland.
You can see surname distribution on this siubscription site for free so many goes a month I think. https://www.johngrenham.com/surnames/ ;
All church records for Dublin and Kerry or most all along with Cork are free on this site. https://www.irishgenealogy.ie/en/ Click on Church, civil records are from 1845 for Protestant marriages and from 1864 for everyone.
Regards
Pat