Not bad at all, and certainly no need for a lawyer unless you have a criminal background, are in debt up to your eyeballs, or are in the midst of committing fraud. The judge mostly just goes over what you wrote in the papers that you filed.
I put "common usage." Basically, that is just a different way to say "well, everybody I talk to calls me that." I did not want to put anything about being trans in because I did not want to be denied the name change in case the judge was not trans-friendly and because there are other people in the court room at time of the trial (people waiting for their trials) who have no need to know my business, but later on I learned that NJ is rather good to us in regards to descrimination so, you can put it in if you want to (my judge guessed it right away and was really nice about it).