@mynameistillian the short answer is you don't have to, IMHO anyway
the longer answer is that with creative writing you're in charge
writing a story for yourself is probably more emotionally rewarding and much easier than trying to guess what other people want
perhaps reflecting on the elements of your favorite sci-fi stories, narrowing those traits down (or even the tropes you hate the most so you can avoid them) might be more helpful long term
you can always change your mind in later drafts