Speak with Tormus Deepforge.
Now that you've learned some moves, it's time to get you a decent weapon. Speak with Tormus Deepforge. He can make you a weapon I'm sure you'll like.
You'll find Tormus here in Ironforge, at the Great Forge.
Muren sent you, did he? Yes, I can make you a nice weapon... but before I do that, I have a favor to ask of you.
Don't worry. It's plenty dangerous and could mean your death; it's exactly the sort of job a <class> wants.