Basically, what will the format of each test be like?
Have you tried looking at the
syllabus for test content?
As Examiners have never been given any instructions or guidance regarding the conduct of NPPL tests, its worth looking at
Standards Doc 19A Notes for the Guidance of Applicants taking the LAPL and PPL Skill Test (Aeroplanes) as this is what Examiners are used to working to.