a prologue or a first chapter of a story is the spear tip of a novel. I've read lots of webnovels that just ignoring the importance of that and resulting them to not receiving many reader due to confusing first chapter.
i'll wrote this under the assumption that you want the reader to stay reading the story after they read the first chapter, if you don't care about those, then you can just skip this one.
it's not unheard of that an author revision their first chapter as much as eight time, just to make the whole story to be appetizing from the start. so you don't have to worry for not doing it right for the first time, you can revision it as much as you need.
lots of author I know believed, that a prologue has to be written in a chronological order like a diary, thus some of them start the story of them as a baby. but I don't think that to be the case.
first and foremost thing that had to put into consideration are the first chapter has to be very relatable for the reader, something that reader could understand right from the start. you can do many ways with this, but the most common usage are determining a purpose of the main character.
the very first chapter has to clearly show what is the end game of the main character, just what are they trying to achieve, and why would they even want those.
like you can show the main character has been living in modest their whole life and now they want to live a lavish life because they're finally reincarnated as a rich person.
or how that the main character got time leaped in life, and knowing something horrible is going to happen in the future and trying to do their best to prevent it.
or maybe you can use the very old trope from heisei era anime when a lame schoolboy who live as the lowest caste suddenly got a beautiful girl fall from the sky right at him, and he tried his best to live a fulfilling live from then on with the weird girl.
to point it in summary, there's 3 things that has to be made clear on the first chapter.
- the way how the main character live their life all this time.
- catalyst (the thing that turn the MC's life upside down)
- purpose (what the MC's going to do, now that everything is changed in a blink of an eye)
the universe setting, character personality, problematic obstacle, antagonist that gets in the way, everything else could wait on the next chapter. because the first chapter are meant to be introduction for the whole novel, not the MC. thus, it has to clearly tell what is the novel all about.