You do not need an appointment but it would be a good idea to make one so as not to be on a long line of the walk in line unless you get there ahead of time for example at 5:45 am and then you might be in with the first dozen or so.
U can but i won't recommend it as there huge line. But they did say that new appointment would be opening in march. So i would wait it out if not in a serious hurry
Thanks! Your answer is awaiting moderation.