Careers in Law, Business, Engineering, etc have a well-defined path you can follow if that is where your interest lies. Because of the path being so structured, it is easy to gauge yourself and receive enough guidance to get to wherever you want to go. The Music industry is not at all like this.
If you want to get into the music business, several avenues can be explored but none of them has a defined career path that you can follow. For example, you can choose to be a singer, musician, sound engineer, etc. If you choose the musician path and want to play Bass guitar, you can take a course that prepares you to play the instrument well. Beyond that, there is no place to apply to where you can play bass, get promoted, etc like in an office.
Getting into the music business is 20 % talent and 80 % hard work. You cannot be afraid of hard work if you want to make it in this business. The first step is, of course, is studying in the area of your choice and perfecting your skill as far as possible. After that, you need to find all the A&R (Artists and Repertoire) divisions that operate in your area. Make a demo, a resume and send it out to them as well as every studio you can think of. You have to promote yourself shamelessly or you will never be noticed.
It is all about being noticed, so until someone takes notice, you have to keep trying. While you do this, be prepared for rejection. Being turned down hundreds or thousands of times will require persistence until you get your shot at your dream job.