Im not high elo or anything but in bronze its definitely more about improving your aim and mechanics first, thatll get you out of bronze fast
after that you should start thinking about which role youre comfortable with (but me personally i like playing flex/fill so its your preference really)
I recommend this video by woohoojin which is a good aim warmup routine that can help you in your journey ig:
https://www.youtube.com/watch?v=JxP2y_q51IE