I don’t have a debit card, only an ATM card. I hope to take enough Euros from here from our bank with us.
Check the exchange rate. Most banks in the US give an awful rate, as do exchange booths at most airports (one of the terminals in Zurich is an exception) and train stations. For countries in the eurozone, ATM's usually offer the best rate, but NOT when using credit cards. I remember the old days, when American Express travellers checks in German marks, French francs, British pounds, or Dutch guilder used to offer really good rates when you bought them in the US, but in some countries, nobody took them except the local AmEx office. Travellers checks have been passe for some time, of course.
When I was working full time in Europe, I could do a three currency transaction, dollars to lei to euros for less than a 2% exchange loss, and I simply held on to any leftover currencies as I would likely have need of them again. Exchange booths in countries using the euro, however, stick it to you on exchange fees. The best rates of all were at the ATMs.
Sometimes fast food chains will take dollars and give you change in local currency at a good rate, but this varies as to whether they will take dollars. I remember when Luxembourg had its own franc and the handful of exchange booths charged enormous fees. The workaround to get spending cash was to walk into McDonalds and buy a coffee or a coke and hand them a US 50 or 100. You would get change back in Luxembourg francs at a much better rate than the exchange booths.