Yes, Java is bit faster - but speed of execution is irrelevant for a beginner, or for automating Selenium. Javascript is a must for web front end developer - but Javascript is more quirky, confusing and less forgiving than Python.
See, you can learn Selenium with any language, whether it is C#, Java, Ruby, Python etc. It doesn't matter whether the application you are going to test has been developed in the same language that you would use to write your test scripts, you can test an application developed using C# in Selenium with test scripts written in Java.
In addition to that, you don't need to learn any of these languages completely for working with automation. You should know the basic stuff and as you go on with testing and creating test cases you will keep on searching about the issues being faced and how they can be resolved, which in turn will enhance your programming skills as well.
For more details please visit: https://nareshit.com/selenium-online-training/