How can I prepare for my M.C.A. test?

M.C.A. stands for Minnesota Comprehension essment. It is a major test that determines my cles next year. I am generally an advance student, but big tests like this make me really nervous. If you have any practice tests (reading) that would help. I'm in 6th grade, but I'd prefer 7th grade level practices, in case the practices are easier than the actual test. Also, since I'm taking the reading M.C.A. test, if there are any important words or things often found on these kinds of tests that you could let me know. Thanks a lot! Best answer goes to best help. :D