Everybody likes these big expensive training courses involving BMW and the like.
I suggest getting a 250 and learning to ride dirt before tackling it on a 500+ pound monster. Build that confidence up with a smaller bike and its a lot less exhausting. Then when you hit those technical sections with the big bike you've seen it before..
Also suggest riding with some people who are experienced dirt riders with some racing background, the only way you get better at riding street, dirt, or track is riding with some people that are a lot better than you. It does wonders.
A GS is a fine street ride with some off road capability but it stands to be repeated that it is far from a beginners bike and people who have a hard time with it are usually the type with more money than experience. No reflection upon the OP at all, just sayin'.