SQL Developer code formatting
I did a google search for the phrase "sql developer code formatting", and the first hit was this:

http://www.thatjeffsmith.com/archive/2014/03/how-to-make-your-code-look-like-steven-feuersteins-in-oracle-sql-developer/

Have a read through that blog post from Jeff Smith, product manager for SQL Developer.  That should explain what you need to do.

Edited to add picture of the relevant options.