Yes, its normal to call people by their first name once you have been introduced to them.
Ireland is the country. Éire is the name for Ireland in the Irish language, not the name of the language itself. Irish people call it Irish, people outside of Ireland call it Gaelic, and in the language itself it is Gaeilge. Ériu was an ancient goddess, and using her name and the suffix "land", the name Ireland came into being, with Éire being the name in Irish, as mentioned in the Irish Constitution.
The first people came to Ireland over 8000 years ago and there names would not be known.
If you are referring to turf, or what some people call peat, then the answer is a bog.
The Republic of Ireland is often used, but the official name is Éire in the Irish language and Ireland in English. Southern Ireland is an incorrect term. In fact the most northerly point on the island of Ireland, is not in Northern Ireland, but actually in what many people call southern Ireland. So "Southern Ireland" is an incorrect term both as an official name and geographically.
Hibernia was the common name used for Ireland by the Romans. It was sometimes referred to as Scotia, a name that was also used for Scotland.
Hibernia was the Roman name for Ireland.
Walsh is an Irish name used first by the Britons to call the Welshmen who arrived in Ireland in the wake of Strongbow's Anglo-Norman invasion of 1170.
Mary
Some southerners from the US call people from the north Northerners while there are some that call them Yankees. Others simply call them by their first name.
Well first it is a republic and the name Republic of Ireland is used to distinguish it from Northern Ireland. The official name, according to the constitution is Éire or in English it is Ireland.
The offical name for Ireland is Éire. That is what you will see on its coins and stamps and other official documents. The term "Republic of Ireland" is not an official name but in the Irish constitution it is said to be a description of it. So you can use Republic of Ireland or Ireland or Éire.
You get your last name from other people and where you live . Once people call you a last name it gets stuck on you. It only happens from your first ancestors.