This isn't normal. Yous will only have been in the class for a few days? It'll be a textual analysis NAB, which is more a skill that is trained than taught, so I can see your teacher's reasoning. But I definitely feel like this is way, way too early.
If you're concerned, raise your concern with the teacher first and foremost.
What'll happen, if it is a textual analysis NAB, is that you'll be given a piece of text you've never seen before - mine was a scene from a play, and you're asked questions on it as if it was a Close Reading paper. But unlike a CR paper, I recall being asked about the name of a literary technique in mine - but I didn't really expand on my knowledge of literary techniques from Standard Grade English to Higher, the ones I knew at Higher were the same as those I knew at Standard Grade. Only thing I learned was enjambment.
It will be timed. I don't know what it's marked out of, however!