Replying to Getting Euros and traveling abroad

I am traveling to Spain in about a month. I have never left the country before and I just want a little assistance on how to get money before I land. Do I go to a bank here in the US and exchange for Euros here or should I just wait until I land. If I wait until I land do I give them a travelers check to cash or can they accept debit? I am pretty clueless on how this all works so any positive advise will be great!

Thanks!