The gears that you obtained from monsters and/or have bought can be upgraded. You can definitely improve the level of your gears including two-handed weapons, one-handed weapons, ranged weapons, magic weapons, breastplate, padding, leggings, shoes and assistant hand gears.

But you must refine your gear before you try enchanting it. If you want to refine your gear, you need to talk to the Refining Master, and choose [Refining/Leveling up equipment]