Listened to the new Williams and Blum this morning and have some tips as a veteran European traveler. Went to Ireland for three weeks in 2016 (which is, sadly why we're not going next month). They referenced their sponsor, Northwest Bank, as a place to get Euros before you go. I recommend that you only get enough to get you from the airport to town as you will get a better exchange rate from a bank ATM in Ireland. Don't get more than 100 euros if getting them in advance.
Be sure to use a bank ATM only, either inside of a bank or just outside. Do not use Eurolink or Euronet or similar continent-wide companies as you will get hosed. Avoid airport ATMs or exchange kiosks unless its a dire emergency.
Always transact and pay for ATM or any credit card transactions in the local currency - that is the Euro. You will be asked either by the machine or the waiter etc, if you want to convert to the dollar - the answer is no. You can check with your local bank to see if their network is compatible with European banks, We've had no problems and we are small town.
It's a good idea to let your financial institution know when and where you will be traveling so your card isn't refused. Some credit card companies no longer require notification but it's a good idea to double check there as well.
Credit cards will be readily accepted in cities, maybe in rural areas, When we were in England last spring, we had to use cards, there were basically no cash transactions. Even a Euro or less for a pay toilet was by card.
If you are going to Northern Ireland you will use British pounds instead of Euros, although I think some places will take both. N Ireland is part of the United Kingdom along with England and Scotland and their currency is the British Pound.
Also if going into Northern Ireland, as of this past January you will need an ETA authorization to enter the country. Not Ireland, just Northern Ireland. You'll need to get it online in advance. It costs about $16 and is good for two years unless you passport expires before then. We connected at London Heathrow on our way home from Portugal in May and even though we never left the airport, we were advised to each have an ETA. You need your passport when you apply and the ETA is automatically added to the passport.
You can check TripAdvisor.com for specific info on Ireland by reading the forum page or checking on activities. The best place to get cash in Italy in 2022 was actually the Post Office.
Last thing, if you're renting a car in Ireland I'm sure you're aware that they drive on the wrong (they say right) side of the road. We were on a tour bus and the first morning as we approached a roundabout I leaned the wrong way and nearly ended up in the aisle. I didn't drive there, but my brother did once and he recommended taking all the insurance you can get. Double check with your personal insurance or any credit card support, but the shoulder on the very narrow rural roads is either a stone fence or thick hedgerows and trees. Lots of scratches.
Have a great time everybody. We'll be watching!! Go Cyclones!