Its not easy to describe where the entrance to baal's cave, as broken valley aint actually very small. And for your level, its better you fly around in dragon form and take down any catapults and nest you see in sight to gain more level, as I suppose you should notice enemy in broken valley is higher level than you. When you are under level, you take more damage occasionally.
If you wish to continue with the story, 1st you need to allocate the quarry office building, which I hope you still remember the quarry mine when there a cut scene played during the early days in broken valley where the guards bomb down the entrance, which they say seeing black ring member. Go there and kill you way up the mine office to find the guild master william and he will tell you a secret entrance to the mine, which is baal's cave. And baal is a lvl30 boss if I remember correctly. After you kill him, you get the sigil, 1 of the tools needed to open hall of echoes. In order to get the shield, which is another needed item to open hall of echoes, you need to travel to Aleroth to find Zandalor. In order to get to Aleroth, you need to trigger the quest for collecting zappelin's part, so that the zappelin could be repair and you can take it to reach Aleroth.
