One more piece of advice about ATMs. Some US banks have reciprical agreements with European banks.
I know if you use a BofA debit card, there are several European banks that you will not be charged a withdrawl fee. If you end up doing lots of withdrawls, it may be worth checking into.
BofA's partners:
Barclays (United Kingdom)
BNP Paribas (France)
Deutsche Bank (Germany)
Santander Serfin (Mexico)
Scotiabank (Canada)
Westpac (Australia and New Zealand)


As far as nervousness, etc., during our first trip overseas, the most nervous time was after first getting off the plane and clearing immigration. We were like, ok, now what? We are in a country where we don't speak the language and don't really know where we are going.
Once we got to the hotel and settled in, we took a couple small trips out and about in the nieghborhood.
So, my advice, have a plan on how to get from the airport to the hotel. We thought we could just jump in a cab and tell them the hotel name (it was a major hotel). That was not the case. So, have the hotel information and a way to get there.
Start off small to get comfortable. I wouldn't go right from the hotel to a full day's tour of the city.
We have also had success in new cities by taking bus tours. It gives you a good overview and usually gives you the ability to get off and on.
Have a great trip!