I have heard a lot of people talk about that level range and how it feels a bit wonky in "what do I do next". It does pick up more later on and gets kind of back on rails.
At that range, you are in a couple of quest packs called Where Dragons Dwell and Veils of Anduin.
Leading up to that, you get to do Laketown of which I really loved, but after that, you end up in Erebor. From there, the story goes two separate directions. You have The Iron Hills to the right and Ered Mithrin to the left.
The Iron Hills is boring as fuck. Honestly. I barely got myself to complete that area.
Ered Mithrin is where its at if you can get past Iron Hills. Erid Mithrin has decent content with dwarves and lots of drakes.
To the left of Erid Mithrin, you will come in to the Vales of Anduin. Now that is an interesting area because there is a story in there about Gandalf that is not in any book or movie. It was a story that they created and got approved by the Tolkien family.
Once you get past that, you will find the War of Three Peaks in Elderslade just north of the Vales of Anduin content. There is a ton of content in the War of Three Peaks including a really cool quest pack called Blood of Azog which takes you far in to the past to experience one of the dwarven wars.
Point is, there is a lot of content worth playing once you get past The Iron Hills.
Riders of Rohan's mounted combat has turned away more people from the game than anything else I have ever seen. It's stupid beyond belief. I struggled through it on my champion. I hated it.
That being said, there are some good stories in the RoR expansion IF you can get past the stupid as fuck mounted combat.
My suggestion is to just dismount and kill anything as it comes to you when you are supposed to be doing mounted combat. Shit dies a million times faster to your normal abilities than it does those stupid ass mounted combat abilities.
Good news is that the mounted combat goes away pretty quickly after RoR expansion.