Euros.

Not if you have a bank account with a debit card you can use at ATM's

It truly depends on your risk tolerance. We always arrive with around 100€. It takes away the need to find an ATM upon arrival. The increased cost is nominal for us and worth the peace of mind.

If you do not worry about finding an ATM and can do without cash for a period of time the wait.

Your choice; there is no right answer.

Thank you for your help with this matter.

Be sure to notify your bank and credit card companies about your travel plans.
Otherwise they will likely freeze your accounts and you won't be able to do anything until contacting them from Europe.
Happy trails!

It will not help you this time but if you travel often a way to do it ,on the last day of your trip take some money out and bring it back home and save it for your next trip .

I always wait till I get to the Athens airport and withdraw Euros from ATMs at the arrivals area. It's quick and easy and much less expensive than getting Euros back home. My home bank charges a large fee just to buy Euros.

Let your bank now what your plans are and when withdrawing Euros always click "without conversion" to not get ripped off by a large fee.

Just returned from Paris- I ordered Euros and British pounds from Travelex- online, easy, delivered to your door and no fee. They will also buy them back. I took enough to pay cash for our apt., pay the car from airport and have some pocket money. Otherwise used a Visa that doesn’t charge foreign transaction fees. I realize this is Greece not France but those are my tips.

I'd be willing to bet that the exchange rate Travelex uses is much less favorable than you'd get at a local ATM. That's how they make the money they need to do what they do. Home delivery is convenient but not free.