late on this reply, but i've posted in this thread years ago about my bootcamp experience. i did hack reactor back in 2015 and have been a software engineer professionally for the past 3.5 years at multiple jobs, so i think i can speak to it from a candidate and an interviewers viewpoint.
to get started, i'd focus on the area you want to learn - web, mobile, server, infrastructure, devops, etc. web dev has the lowest barrier to entry imo, and most bootcamps focus on this. i can vouch for these bootcamp prep courses based on personal experience and from word of mouth from friends (i did hack reactor's before the immersive):
https://www.hackreactor.com/prep-programs/
https://www.appacademy.io/bootcamp-prep
https://www.codesmith.io/bootcamp-prep
i went from learning how to code to a job in about 6 months or so, so it's definitely possible not to have years of experience if you're worried about that. even though i only touched javascript in the bootcamp, i've written everything from javascript, php, swift, golang, java, and sql at my various jobs so don't stress learning more than one language. most of my job is reading docs and stack overflow anyway lol. but yeah, feel free to reach out if you want some more insight. a few in this thread have in the past. good luck!