This story belongs to the xianxia genre which evolved from the popular chinese wuxia martial arts genre. For the most part it will more closely resemble wuxia, but the xianxia elements are not negligible, so I found it better to include it in that category.
Since this genre originated in China, and I'm trying to be as faithful as possible many words will remain in Chinese, when translating them turns them nonsensical, or would result in a string of words. This is a list of common terms and their explanation, as they show up in the story. If you're familiar with xianxia/wuxia you can skip this section entirely.
Jianghu - 江湖 (lit: rivers and lakes) - The martial arts world. Think of it as the Chinese version of the medieval, european inspired, fantasy setting. It's based on fictionalized ancient China, where magic, monsters, and (chinese) dragons exist.
Cultivation - training in martial and mystical arts, generally in order to become powerful and increase their longevity. Meditation and the cultivation of Qi /spiritual energy, are common practices among cultivators. Weapons, objects, and musical instruments can be used to battle.
Sect - a "school" of cultivators so to speak. They have a long tradition, and often specialize in specific martial arts styles, and can have different functions. Some sects focus on sword fighting, others can refine pills and elixirs to help with cultivation, others can focus on medicine or weapon's forging. They all train in combat in some way (in this story), but some are more adept than others. They are composed by disciples who live in the sect and are trained by the older generation. Not all sects are good.
Sect brothers/ sisters - I will refer to them in this way in the narrative, but characters will refer to each other as shimei (younger sect sister), shijie (older sect sister), shixiong (older sect brother) or shidi (younger sect brother). This designation isn't actually related to age, and instead with the order of initiation into the sect. Disciples who started training later refer to those who started earlier as older brother/sister. This will change depending on perspective. A character can be called "shidi" by his seniors, and "shixiong" by his juniors. Sect brothers and sisters are not necessarily blood related.
I will keep updating this list as more pertinent terms come up, and if any of you have any questions about any term or expression. Feel free to correct me if I get anything wrong as well.