Both "for example" and "for instance" are accepted, here. Maybe there was a typo somewhere in your answer? (People sometimes miss words in this one, or type "to to" instead of "to go," or something like that.)
Right: "go on a journey" would be "ir de viaje." "Ir al extranjero" means that you're leaving the country (and "go abroad" almost always means the same). "Go on a journey" means you're going on a long trip, but doesn't specify whether you're leaving the country or not.
9/13/2017. Using Chrome I answered with "I want to go to abroad, for example, to Italy or Spain" and it was marked wrong. They wanted for instance (even though example was on the drop down suggestions when you hover over ejemplo)