About the fanfiction, here are some pointers:
1. Try leaving space between paragraphs. Your fanfiction looks too cluttered.
2. Use capital letters when referring to a person's name.
3. Try to make paragraphs shorter and usually use a new line for dialogues.
4. Use Bold when you are making a time skip or line break or when you are writing author's note or when writing Percy POV or Annabeth POV or something like that which isn't related to the main content.
5. Focus on grammar.
6. Instead of Percabeth, write Percy and Annabeth.
7. Use punctuations.
8. When writing the chapter name, keep the first letter of each word capital.
All in all, I think you should focus on aesthetics as it is a very important part. If you allow me I can show you what I mean. Just share the script of any oneshot with on my profile. I'll rewrite it and send it back to you. I swear I won't use it in my fanfiction.