Hi and welcome to Inspire Pilots.
Many of us on here have CAA approval and hold PFAW so have gone through the same thing. I wouldn't worry too much as your NQE will take you through the process of what must be included in your ops manual and most will give you a template of the headings that must be included.
The important thing is it must be YOUR document and contain your own working practices, checklists and emergency procedures as well as operational limitations (maximum working ceiling, Take off mass etc etc). You will cover all these thing and a lot more during your ground schooling and after you have completed that and sat your exam you will have a lot more confidence in being able to write your own manual.
Nearly all PFAW holders will guard the contents of their manual like Fort Knox since it is something that they have worked on and authored from scratch. The important thing is YOU must understand why certain things and working procedures are in there rather than plagiarise someone else's (I'm not suggesting you would do that).
For most people writing a 50 or 60 page ops manual is the most daunting in working towards PFAW but once you have completed your Groundschool, things will become much clearer
Then all you have to do is pass your flight assessment!
Good luck.