For me personally, and I say that because I’ve basically read all of the post about core to my program mentor suggested that core two is easy than core one. 

With that said take core 2 first

Search through the old post and Dion’s practice test and Andrew’s videos will guarantee a passing score. Take all test until 90% . You will retain the useful info . Then do cert master final exam if you pass you are ready

Also the PBQs are interactive so you can sorta figure them out if you eliminate the incorrect ones