So I'm off for an American odyssey, but I am wondering how to pay for the little things like living expenses. I've got a US checking account, but there's not much in it, and I just heard that they closed my credit card due to inactivity.

Here, I've got a fistful of euros (I am usually paid in cash when working in eurozone), plus CHF on the account. Where should I change them for dollars - here or there?

At your bank here in CH.

Even the euros? Would it be better to change those in Germany?

It works with Euros also. Last time I tried exchanging money in Germany they asked for a bank account at Deutsche Bank and Sparkasse. Reisebank did it but with some hefty fees...