As far as six sigma is concerned, one can generally, get only an idea of it, if you do just a course, even if we do black belt level. We start learning only after doing some real six sigma projects and achieve something like process time reduction. If you get a mix of six sigma project failure and success with six sigma project, all the more better, as the failure will teach a lot of six sigma, and success gives you confidence.
I don't think just a course will be of much help ( I believe you are looking for career lift from course, hence this open, but with good intention , sounding like harsh reply).
There are some trainings like FMEA training, where you sit for two hours; you could be made to understand basics of FMEA, how to draw the FMEA chart, how to interpret FMEA chart etc. but I am afraid, six sigma is not like that !!!
But Six sigma with real time project exposure, will help you in getting the "Elevation".
All the best,