Studying guidance requested

Hey guys, 

I have passed the intro and trying to move on to the certified. I haven’t had the opportunity to sign up for the certified, no spots available, nothing near me, I also want to take the deductive class first but I haven’t because of lack of availability. I want to keep up with my studying until the opportunity is right, what is the best material to use to study off of for the certified, how  important is it to take the deductive class first?

Thanks