1. college students are generally 18-22 here; college is 4 years and is, very generally speaking, essentially synonymous with "university" - the term merely differentiates it from, say, a technical or specialty college. 2. Given the plethora of "study abroad" programs my college in the US has, I doubt you'd have too much trouble going to an American University. You could either try to transfer from a Norwegian college, or you could simply take an american exam (the SAT and ACT are the two colleges look at most) and apply to an American university like any other student. I'm currently at the University of Washington in Seattle, Washington, USA myself and it altogether wasn't that difficult to get into, so you shouldn't have too many problems.