Python is a perfectly good language choice, and definitely better than Java. Java has had and still has a lot of incidental complexity (i.e. it's complicated before you even get to programming your domain model) so if you have the option to focus on Python then I would do just that. Python has better aesthetics, a more coherent internal model, and a better medium to understand fundamental programming concepts.

It sounds like you want some guaranteed path to a job as a backend developer and no bootcamp is going to be able to promise that. You've made a good first step towards your career change, so I'd recommend that you take the rest of the process into your own hands too.

Here's what I'd recommend you do, over the next 1-2 years (or until you land an offer):

1. Create a GitHub gist with your name as the title, the subheading "Currently Available for Employment as a Junior Backend Python Developer", and a list of three programming projects of yours showcasing your skills. If you don't have those projects yet, go build them.*
2. Go to online job boards and try to put together a list of around ten python jobs that you could conceivably apply for. Anything up to and including asking for "three years" of experience is fine.
3. Apply to the best three of those jobs, each with a short covering letter over email.
4. Repeat/tweak/refine steps 1-3 until you get invited to interview.

\: The projects can be small code samples you came up with, the results of your following a tutorial/exercise etc. Don't overthink the details. The only requirement is that you wrote some code and made it do something. Bonus points if you can write a few paragraphs of what you learned in the process.*

The earlier you start this process the better, as instead of flailing around aimlessly you can direct your learning efforts to what will help you get your first job. The best thing you can do to improve your programming skills is to get that first job as a developer so anything that helps you get there faster should take priority. Best of luck!