O'Brien's from Waterford

I am trying to see if I have any living relatives in Waterford Ireland. I am the descendent of Samuel ( 1803) and Elizabeth (Devlin) O'Brien, whose grandfather immigrated from Waterford to Baltimore Maryland (around 1800). Their son, William H O'Brien married Elizabeth Wendling (Pittsburgh PA), of which, my grandfather Samuel Cleveland ( 2/10/1885)was one of 11 children. I am traveling to Ireland in July of 2020 and would like to contact any family I may have. Not sure where to start, any suggestions would be appreciated. Thank you, Juanita "Nita" O'Brien O'Toole