Bro, it's only 1st step of the game and we have only cleared that. Moreover, if you need to prepare for exams like nab, firstly be sure to check out the syllabus that is the only guide you need. This exam was of 25 English, 15 analytical, 20 IQ i.e 60 marks are there to be taken without any preparation. But, if you are bad in english then improve it by reading grammatical books and downloading apps on your mobile for english improvement. Rest i.e., pakistan affairs, islamiat and eds. Do last 10 papers of css i.e., only mcq part that will give you a rough idea, where you stand in terms of lacking in preparation and it will be the best guidance you can ever get.