How to revise for GCSE Edexcel History? + any resources?

I just started Year 11 and am working up to a 9 in History (I'm currently on a low 8), but I'm finding it really hard to answer some of the questions:
I'm doing Medicine through Time, and I struggled with 2a and 2b (the source questions). Does anyone have any resources that might help me with this? Preferably answers for 2a that I could memorise (e.g., types of sources and why they are helpful/unhelpful).
I'm also doing Superpower Relations and the Cold War, and I struggled with basically all of the questions (I got an 8 in my Year 10 mock, but I really want a 9). Does anyone have a list of all the possible consequences, narrative accounts and importances of every event that could come up on the exam?
If you have any other resources or advice that might help, I'd be eternally grateful! I currently use my school textbook, a CGP textbook and a Pearson textbook (is that overkill?? lmao)

Hi, I did edexcel and did do superpower relations and Cold War, also Weimar and Nazi germany, crime and punishment over time, and Anglo Saxons/Normans.
I would highly recommend the Hodder Textbook for the Cold War module. Or the Pearson revise one for medicine over time I heard was quite good from a friend.
It’s not overkill to use multiple textbooks, I self studied and also used BBC Bitesize or Teach videos if it had any on the relevant topics (don’t think it had any on the Cold War though).
Would definitely recommend flashcards for history, but mostly for remembering dates/timelines of events. You could buy some or make your own poster of the timelines.