I need math help!!!!!!!!!?

I am in 6th grade right now and I'm taking Pre-Algebra. I get A's, I get good scores on my tests and everything but my school does Saxon Math. It's a Charter School. Next year I'm going to a public school and they don't use Saxon. When I signed up for electives I chose Algebra instead of Pre-Algebra. Algebra placements are in one week and as I'm looking at this new method there are things in the pre algebra book that I haven't even ever heard of such as the quartile of a set of data or whatever this sign means: | | Now I'm getting scared that I'm not going to pass and that I'll have to take Pre-Algebra again. Also, even though I've learned it I've had a really hard time with graphing lines and finding numbers to the negative exponents. Can somebody please help me?