Re: I came second in my class
Here, it would be normal enough to say "I got the second-highest score in the class on that test" or "I got the highest grade in the class."
You will hear "grade" and "score" used interchangeably in that context, but "mark" is a little less common.
The results aren't usually posted - it's by talking to each other that the student figure this out.
I'm not a teacher, but I write for a living. Please don't ask me about 2nd conditionals, but I'm a safe bet for what reads well in (American) English.