If you are starting from scratch, go on one of the fast track courses. I wouldn't normally recommend them because I think you would be cramming them and then forgetting the info as soon as you completed the exam.
If you aren't starting from scratch - work out which areas you are weakest, perhaps by using an online test such as airquiz, then book an instructor for as long as you need till you get those into your head.
Best of luck!
And do try to learn the material rather than just bash question banks.