My best travel advice: don't panic.

Stuff goes wrong. You miss trains, or you can't find a cafe, or you lose your money, or you can't find a hotel room, or you miss your flight, or you can't read the language and end up on the wrong metro line and are wandering around Moscow in the dead of winter trying to find a cab.

Very few of those things are life-threatening, and most of those problems can be solved with a smile, a helpful stranger, or judicious application of monetary funds. The important part is to keep a level head, which you sound like you have.

(Also, always carry a bit of food on you. Few things suck more than being lost AND hungry.)