I’m not much of a Java person, but you should find that Selenium server is already started with that config. You’ll need to compile your Java file, ensuring that its dependencies are satisfied, and then run it.
Create a new run key with something like this:
javac TestLogin.java && java TestLogin.class
The first command will try to compile it, and the second one will try to run it.
If that does not get you unstuck, please post your config.yml file in a pre-formatted block, so readers can make more specific suggestions.