No one has explained it to me but what is the History A level exam?!

So, apparently I'm supposed to just know this, but I'm confused and so are a few of my friends doing the same course.
What is the history a level exam, I know there's a paper and an essay, but when is the essay done, in lesson? How do I get the information? I get Google and libraries but I'm not able to buy anything or go anywhere so how am I supposed to go to a library? What if I can't find the info I think i need and I'd I have looked through a book and can't find any relevant historians, how do I find some relevant views?
I've been putting this off for so long because I just shut off if I don't understand something but now I'm ultra stressed and I have no idea what I'm doing and I've tried asking my teacher and she's kinda useless to be honest.
If anyone can just give me a quick general run-down, it'd probably help more than anything else I've been given.
I'm finding it hard to learn a course without a teacher too cuz I've never done that before and I've always been really bad about revision so how did people do that?

Assuming you're talking about AQA A-Level History here.
First there's 2 main exams each worth 40% and a coursework worth 20%. The coursework is on a set component which is done in 2nd year, I had the events leading to the fall of tsardom 1824 or smth to 1914. You get a selection of questions you can choose to answer which is 4500 words long, you get like 4 months to complete independently. You need to find historians to support your arguments as well as primary/contemporary sources in alignment with your essay. Usually your teacher should brief you on how to find these, either online, school libraries, public libraries, etc.
The exams exams are on the two components you're doing, I.e Tudors and Nazi Germany. These consist of 2x 25 markers and a 30 mark source question. These exams cover both AS and A level content.
This subject was aids imo it's near impossible to cram I scraped an A off like a couple days revision for each exam so if you end up choosing this you need to pattern revision from Y12 or minimum early Y13. The coursework is light though your teacher should brief you fully when you get around to it I got 37/40.