Re the best way to get currency. Don't forget just how those "change bureaus" actually work and none of them work for free.

They either offer what looks to be a very favorable exchange rate but at the same time often charge a higher commission. Or they advertise "no" or "low" commissions and then give you a less-than-favorable exchange rate.

Using an ATM will generally give you the best available exchange rate. But, as someone has pointed out, you may incur charges for using the ATM. Check with your bank to see if it has a relationship with any foreign bank. For example, Bank of America has agreements with several other banking systems in Europe and whenever I can I use those ATMs to minimize charges.