Since I am new to this, I'm not sure what I like more. I have also been self-teaching before this course but have not gotten deep into a particular language's fundamentals. I want to decide on a language and stick to it before I move to a new one after the first language is learned, but it is difficult deciding which language to start with. I want to develop medical software and medical mobile apps.
My advice to anyone learning to program is to not obsess on the language.. You SHOULD learn all languages.. Same as learning human spoken languages - the more you learn, the more ways your mind can interpret a new problem set. Learning them at the same time isn't a big deal (just like growing up in a bilingual home). Your language and your software stack are guaranteed to change 3 times in your career. Don't assume you're going to choose the "right one". And you wont waste any time learning one you never wind up using.
As a person who works on linux and OSX desktops, I have a personal bias against working for companies and software stacks that require C# or Visual Studio. But this is not due to their technical merits, but instead the OS as a platform condusive to efficient CLI toolchains and container management. But aside from that, I can use vi/IntelliJ-suite to write most languages, so language isn't a real concern. If you're windows bound, pretty much everything is available to you (through VMs and docker).
Any AI (which is a hot employment topic for the forseeable future) would like python skillz.
I personally love Java (and Android's Kotlin varient) for it's very very well designed multi-threaded libraries. go and rust are newer and thus do a slightly better job at this, but due to the open-source nature of java and editors that auto-reveal function call source code, it's very easy to learn how vendors implemented MT code and various other algorithms. Python should be equally "open" to 3rd party library review (and thus again how they solve complex problems), though a lot of times, I see python resorting to compiled C-libraries (and thus the cost to crack open the code and or trace through the code becomes too burdensome to bother).
Sticking to a language before moving on is a common goal. However, in reality you are going to transition as you find languages that better suit you or your organization's requirements. Start with Java, not because it is optimal for your end goals, but because it will teach you what you like and dislike about programming and because your instructor is more familiar with it. That will give you a valuable perspective and allow you to make a more informed decision later.
There are many ways to solve problems in different languages, but the "best" language pragmatically is the one that you feel most comfortable using. In that respect, programming is like woodworking- you want to let the tool do the work. If there is another language that is "better" objectively but more difficult or confusing to you, you will counteract the anticipated benefits by having to struggle to write code.