So I decided to read the first two chapters. And there was somewhat an overall problem with what I read.
Well, I’ll start by saying that I wasn’t put off by the beginning of the first chapter, but I didn’t notice that the dialogue between the girls is a little stiff and weird. I’m not sure if English is your native language or not, but if it’s not, then, it’s not too bad. However, it’s still easy to tell that you’re having a bit of trouble making the conversations flow properly, and even realistically.
There’s also your grammar. I’ve found words that didn’t seem to belong where they were placed. For example, in the first chapter, when Chayeoung is talking, at the end of the sentence, there’s the word, “huh.” It doesn’t fit with the sentence. She’s not asking a question, nor is she realizing anything.
With your tenses, I feel like you’re overall tense is past tense, but it seems like you threw in the future tense. For example, when Chaeyoung was responding to Sana and said: "I walked down the aisle in my pyjamas…And she even tries to chase after me!" It should have been “tried” instead. As a side note, the word pyjamas, is actually spelled pajamas; and the elipsis (…) you used, wasn’t really necessary, I don’t feel like. You could have just replaced it with a period.
For Dahyung’s lines, it says, “she doesn’t know the woman, but she already doesn’t like her.” I guess it’s something you could say, but then, at this point, it already sounds like they’re definitely fated to meet the girl. It would be more natural for you to say something like: *She sounds like a weirdo. I hope we don’t run into her again." Just imagine a realistic scenario of your friends or you reacting to a stranger coming up to you or them with a weird or unsettling conversation. Chances are, you’d never see that person again, or at least if you know you’re living or have more chances to see them, you’d try to avoid them afterward.
So I overall, I think you should try looking towards yourself, and even others, to get more realistic conversations in your story. I wish I could’ve gone more in depth with this, but I didn’t have much to work with given the format
I’ll also leave a reference for you to check out. Hopefully, it could help you. You also have the option of taking fun quizzes on this site, so that you could better your grammar.