Swapna,
Yes, you have to take a course. You don't have to do it before taking the
test though. You do have to take it before receiving the cert. (step 7)
Steps 1 and 2 are mutually exclusive. If you have already taken a course, you get to do step 2. It sounds like you haven't, so you do step 1 instead of step 2.
Then there's the three parts of the exam:
Step 3 - multiple choice exam
Step 4 - do the assignment and submit it
Step 5 - skip this step. Don't fail
.
Step 6 - take an "essay exam about your assignment
Step 7 - prove you took the course mentioned in step 1 or 2