Help Requested. Why is the game taking me to Caverns of Time?

Wanted to level up demon hunter. Finished intro quest. Started Legion with Chromie. So now I have the quest: "Onward to adventure in the broken isles." But the first step is "Take the portal to Caverns of Time." Once I get into Caverns of Time, there is nowhere to go. It's just a dead end. I am really confused.