You can view all of your past test results by clicking the Past Test Results link in the sidebar. More specific instructions are below.
If you just took a subject test (i.e. Biology Test #1):
The table is ordered by date taken, so you're most recent exam is at the top. Click the exam name to begin reviewing that exam.
If you just took a full length exam:
The table is ordered by date taken, so you're most recent exam is at the top.
Full Length exams are broken into their individual sections (Survey of Natural Sciences, Perceptual Ability, Reading Comprehension, Quantitative Reasoning), so start with Survey of Natural Sciences and proceed from there.
You can use the AA Calculator to determine your AA (found on the full length simulation page).