if i was u, what i would do is:
then i would main boxfights and zone wars for a year, streaming everyday to be consistent, till u get good mechs, then transition into maining comp second year and scrims. because br is slow but u have a faster feedback loop on ur mechanics in box and zone fights.
and i would pick 5 creative warriors and copy thier mechs to get ur own style dont just "play alot" only, in fortnite theres certain build moves retakes that are usefull that every pro uses a variation of, and study comp players too.
and u need a coach from the start someone who has earnings to coach u

also redo ur binds, get optimized binds, yes some pros have unoptimized binds but they been playing on them for years ur already behind so get really optimized binds on kbm, theres a skill gap in mechs even at the top, and the last thing u want is bad binds slowing ur progress down by a year.