I'm a recent graduate from Le Wagon coding bootcamp trying to find my way to a career in the high tech industry in Israel.
There are a lot of things to consider before just signing up for the first boot camp that catches your eye.
Most boot camps fall into 2 categories (as far as I've seen), though there might be exceptions: full stack development and data science. If you have a strong math background (and you like math) you might want to consider the latter, otherwise you might find it too dry and boring. Full stack development is equally difficult, but in a different way (more on that later). I'm focusing more on the full stack path here because that's the path I took.
In every field there's an impossible amount to know; you're never going to know everything. After a boot camp you're likely only going to know the minimum amount to get a job. Also the playing field is always changing and growing. You're going to be on a path of constant learning. As I mentioned before, I've already learned (not completely, but to competence) two other frameworks since finishing my boot camp.
A lot of people with whom I attended boot camp were sent by employers to improve their understanding of their respective industries. I also knew at least one person who was sent to boot camp by an employer on the condition that he'd work for them when he finished.
In my experience these situations are not very common. Most of the people I know who attended boot camp are still looking for work or got jobs in other related fields. I'm still pushing to find a job in this crazy Corona world. It might also be best to look for a boot camp that has career services to help you look for work when the program is over.
While working on my final project of boot camp I was my group's back end guy. I loved working on that database tables and seeding data and I loathed doing any front end work. During the end of this project I noticed some design elements that I really didn't like and went ahead and changed them.
This was the shift that lead me to realize my affinity for front end development. I'm now working towards mastery (competence) in React. I would have never guessed 6 months ago that I'd be learning React and looking for a job as a front end dev.
They're called boot camps for a reason. It's a TON of work over a short amount of time. That being said, you're not in the military and you have the choice to slack off if you want to. DON'T. The more you learn the more you're going to be successful, and the more you're going to be able to do on your own after the boot camp is over.
Learn from your instructors as much as possible. As I explained above, you're not going to know everything after the boot camp, but the more you do know the better. There are little things that you may not know how to do, but you should. My brother-in-law attended a boot camp and afterwords he didn't know how to deploy his website. Now he's a pro at it, but it took him a little while to figure it out on his own.
Enjoy yourself while the stakes are low. You'll be under a lot of stress, but you'll be working on fun projects that interest you. This may not be the case when you enter the work force, so have fun!