It depends on which level and use cases you prefer to work at. Close to the machine? Rust is great but if you need to find more job opportunities, then take C/C++. Java has many job positions but I suggest Kotlin over it. Think about it as a better Java, but fewer job positions. Do you want to do your own projects? So a productive language like Ruby is way better. Like to program front-end apps? Take JS. Find your passion.