What EXP and Light levels are you?
I recently finished the "main story" of The Taken King expansion myself and a lot of stuff is locked until you hit level 40. A bunch of stuff is not even visible.
As soon as you reach EXP 40 a lot more of the content shows up. Even then you need to be a certain Light Level to actually play some of them, anything Heroic for example (light level 240+ from memory).
