might fail a course… help!

i unfortunately opted for an elective that sounded interesting over one that is easy. it is my hardest course this semester which absolutely sucks because it’s an optional class. i don’t want to drop it in case i can redeem myself with the last quiz and the final exam. if i do fail though, what do i do? i want to get into a masters program. is this even something big to worry about? i’m only in my first year. i don’t know what to do… help lol