As far as I know all credit cards charge a 1%-3% conversion fee except for Capital One. We got one for our European vacation last Oct, then canceled it upon return. In general, credit cards give you the best conversion rate.
I’d buy a little Euro (no more than one or two hundred from your local bank) to tie you over for the first few days. Once you check that your bank ATM works in Europe, then just take cash out of ATM as you do here. As with credit cards, you get the best exchange rate. If you take the max out ($500 USD for my credit union), your transaction fees will amount to 1% or so. The airport exchange is the most expensive way to go.
I belong to California Coast Credit Union and I had no problems finding ATMs in Paris, Amsterdam, Brussels,
