Realistic Expectations and Request for Advice

Hi everyone, so today I’m incredibly bummed out, I got an 80 on my exam. Now there’s only a 5% leeway for my final (something that I believe I may be able to do) to receive an A in a class. But there’s a possibility of me getting an A-. Never in my college career have I received such a sudden low grade and I genuinely believe there might be a grading mistake or this is a fluke or something.
My question is, what is a “good” GPA to have for any of the top 7 LS?
Secondly, how do you people study for an exam in which there’s a huge, pictureless, wordless textbook that we take an exam over and the professor is a decent lecturer, however the exams themselves have alot of application questions moreso than anything else? ( Surprisingly, this course is called “Business Law,” but I didn’t take it JUST because I want to go into law school, it’s just a requirement for my minor. )

An A- or B is fine as long as your aggregate GPA is at least a 3.7 or higher.

Study for law classes the same way you study for other classes. The “Nutshell” and outline books, describing different fields of law, are helpful in giving summaries.