Try to figure out your requirements first. What am I going to create, which platform etc..
You will likely need multiple technologies to cover all aspects of the "system" you are creating.
Then select the language/s that best fit the requirements.
Learning programming models is more beneficial than learning the details of a programming language and can be as fun as programming.
The language is no more than a technical artifact.
If you want to learn java because you want to create a game, I advise reading some books on Object Oriented programming and the site of Oracle ( the current owner of java ) http://docs.oracle.com/javase/
and a proper editor like eclipse.
You may be overwhelmed if you didn't read the proper books or get hooked.