In general, the Anonymous Noise anime is comparable to the manga. Some minor details might be different, but the core elements and themes remain intact. There are also visual and audio enhancements in the anime that add to the experience.
There were some differences between hiding one's name and being anonymous. Hiding one's name referred to hiding one's real name from others. On the other hand, anonymous referred to not signing or signing one's real name, which meant concealing one's identity, personal characteristics, or not explaining who one was. These two words had different meanings.
My answer may not be accurate enough. From what I know, anonymous web novels are usually not considered authors because they don't leave any public information or personal information. In web novels, there was usually a team of authors or an individual responsible for the entire work, and anonymous could be one of them or just a character in the work. If you want to know more about anonymous, I suggest you check the relevant online literature community or forum.
An anonymous person referred to a person who did not leave his name or identity. It could also refer to a person whose literary works, such as articles, novels, and poems, had no designated author. In literary works, anonymous names were usually used to avoid copyright disputes or to protect the integrity of the work.
As for how to pronounce it, it sounds similar to "name" but "name" usually has two sounds of "name" and "death" while "anonymous" only has the sound of "death".
As I don't know the story, it's difficult to say. But surely the anonymous girl is a main character. There might also be characters like her family members, friends, or people she meets during her journey in the story.
There could be a skilled swordsman as an important character. He is likely to be the protagonist, with his excellent sword - fighting skills driving the plot forward. Maybe there is also an old master who teaches the swordsman some crucial skills.
I don't know as I haven't read it. But typically in a light novel, there could be a young protagonist, perhaps a male or female teenager. There might also be some side characters like friends, family members, or mentors who play important roles in the story.