It's been over a year since I took my GCSEs so I'm not entirely certain it's the same paper but my answers are fairly generalised. I was in the year group when the specification was first changed and the grades changed to numbers rather than letters. I managed to get a 9 and I'm now taking lit and language at A-level. My tips are:
Practise!! Even if you don't write essays, finding text samples and annotating them will help you firstly get faster at it (so that you're better at spotting features, saving you precious time in the exam), and secondly will help you get used to various types of prose. And it'd be good to find random images online and try writing short, timed pieces if creative writing on them.
I'd recommend saving the past papers until later in the year in case your teachers want to use them as mock papers, so that you get an accurate idea of what your grade is and where to improve. That being said, the material you use to revise with doesn't have to be from past papers. You can search for online extracts from fiction/non-fiction and (if this is part of the spec?) articles and do the same.
Be sure to read plenty (whenever you can) and a good variety of types of texts and levels (less to more academic). This'll mean that you're accustomed to writing styles and will really help you on any creative writing tasks, as well as boosting your vocabulary for the whole paper.
Know which features are higher level, to pick out of texts and to use in creative writing. This is usually structural things such as narrative perspective (is it in 1st/2nd/3rd person, why, do we trust the narrator, what kind of tone is put forward, how, etc) as well as overall textual structure (repeated phrases/concepts/imagery, do we change location or perspective, what is the text focused on and what does it move to, etc) and more complex grammatical features (subordinate clauses, semi colons, etc). In creative writing, vary your sentence/paragraph lengths for effect. Essentially (and sadly), creative writing at GCSE can be a box-ticking activity to show you know how to use features. At my school (and most others) we used an acronym to remember all the features we needed to include. I would write it at the top of my page and tick things off as I went. BUT the higher marks come from making it seem effortless, not like you're trying too hard (which is where the practise comes in).
This is where your teachers will be very useful, you could even ask around the English faculty to see if any of them mark for the exam board, as these teachers will have a much greater insight of what makes a good answer. If any do, what you want to find out from them is A) what gets higher marks and B) what tends to let students down.
When analysing, embed your quotations. So rather than saying (for example)
'The writer uses verbs. This is shown in the quotation "Katie kicked the ball"'
use the quote as part of the sentence, like
'Judicious use of verbs is evident when "Katie kicked the ball"'.
Essentially, don't set up your quotations, blend them in.
Utilise your lessons. Honestly, I had a right laugh in English in year 10/11, I loved it, was regularly distracted, and sat next to a girl who's since become one of my best friends (English was our origin story). I don't recommend that at all, but if you're going to do that, pay attention at the right parts. Engage in class discussions, find out what other people in the class think about texts, recognise who in your class seems to have the best ideas and pay specific attention to them. Putting that extra bit of effort in when you're in lesson saves you a bit of time outside it.
If you don't already, watch Mr Bruff on YouTube. He's a saint!
Lastly, don't worry too much. The fact that you're looking into how to get a 9 shows that you're doing well and working hard, you seem to have the right attitude. In the end, if you're stressed, it may mean you sleep less or struggle concentrating and don't retain enough information, which is the last thing you want. So, obviously, work hard. But not to breaking point.
Best of luck!! You've got this