The best CISSP exam advice I received was to remember that, above all, it's an English test.
I took that to heart and -- it wasn't pretty -- but I managed a 1st-time pass.
All the best,
Focus your learning on the domains and subject areas like encryption that might not be familiar. The Candidate Information Bulletin is your BEST friend. Work through scenarios to develop deep critical technical thinking - that will be the game changer for you. Good luck!