You need to make sure not to quote questions actually asked in the exam. Also make sure not to ask the same question as you found in any other course or book etc. Make sure that all the explanations you put on screen are your own and not copied from elsewhere.
I don't think you need permission from anybody, but make sure not to breach anybody's copyright nor plagiarise anybody else's work.
Also, work out how you can get paid for such a course. Don't put it out free of charge.