He will have 3 books though, both my Dcs did/are doing Shakespeare which in this case is Romeo and Juliet, then they have to do a 19th Century text so a Christmas Carol then a modern text, ours is An Inspector Calls.
For A Christmas Carol they are taught the themes of isolation, supernatural, poverty, family, charity and Christmas. The whole point in AQA giving the extract is so that students have something right in front of them to pull examples from. There is no foundation/higher paper for English everyone sits the same single papers. The one on fear is the opening of Stave 4. If he doesn't know the book then how does he expect not to feel like this for both English Lit papers?
Ds1 who sat his GCSEs in 2019 listened to the audio book whilst reading along with it as it is a good way to get it into his head. School organised for them to see the play at Christmas of year 10 but he also watched the film too including the Muppets version.
Fear isn't specifically covered as a "theme" but that whole opening extract of stave 4 shows a fearful Scrooge, he gets down on one knee and the ghost "filled him with solemn dread". Scrooge fears being poor hence the penny pinching life. You relate this back to Dickens' own childhood of being suddenly poor and then working from a young age. You have to take a step back, acknowledge this is a work of fiction and why Dickens wrote it. Consider when it was written.
It also isn't about learning full quotes as such but learning the key words from those quotes that you embed into the sentence. You do have to know when things occur. I cannot speak for English papers but we were told by school that the maths higher paper has around 50% of the content designed to separate the 9s from the 7s. That is why they want you to be a comfortable 6 to be entered in for it. The English paper is not going to be easy for everyone, some children will get 2s and 3s due to the grading curve.
In a way it is good you found out now so that you can talk to school about supporting his learning.