Are my PSAT scores good?

I got a 470 on critical reading, a 560 on math, and a 500 on writing skills. So my overall score is a 1530. I did not study one bit for this test so on the actual SAT I should do better. Also is the SAT scored out of 2400? what about ACT? Because I was looking at scholarship requirements for a 4 year army rotc scholarship and it says a score of 920(math/verbal) is required. That just sounds way too easy. Is it because it's only 2 sections and not the whole thing?