Hi, all these languages that you mentioned are equally important in order to become a successful web developer. In the end, it is totally your call as you have to decide according to the company's requirements. Also, you need to learn different languages for both front end and back end. As it is, HTML, CSS, and Javascript are front end languages and Java, python, ruby, etc are all back end languages.
Popular programming languages for the web include PHP, Python, Ruby, C#, and Java. There is also a form of server-side JavaScript– Node.js, which is a run-time environment that can run JavaScript code on the server.
You can choose from the above options and then work your way around learning the languages. You can also learn to be well versed with both front end and back end languages.