Are you doing specification A or B because it depends generally.
But you should be doing exactly 4 papers, each exam being 2 hours (so 1 hr per paper).
And again, the topics depend on which part of history you're doing (like I did Elizabeth, USA, Cold war and Medicine) so once you find those out, you should be able to go to the Edexcel website and find your individual topic list.
A tip I give from someone who went from a 3 to an 8 in her GCSEs is that taking note's is really going to waste your time. I went on google and typed out knowledge organisers for each topic I did and memorised them before the exam. Obviously everyone's method is different but my strength was memorisation so that's what I did. Unless you're not in year 11 rn, taking notes is beneficial but once ur in yr 11 don't bother, just memorise the content given to you in the pdfs of each knowledge organiser.
I'd also recommend using an A3 paper and for each sub topic/topic do a mind map on Individuals and Themes (ie for individuals i'd write Lester for medicine and Supernatural believes would be the theme for medicine).
But history really depends on the structure of you're questions, you could know all the content in history and if you lets say write provenance in question 1 when it's not needed, you're capped at either 0 or 2/4 depending on whether your whole answer revolved on provenance.