A "guilty plea" means admitting that you have committed a wrongdoing or broken the law. It is a person's acknowledgment and acceptance of their guilt in a legal case. Full definition
You must enter a not guilty plea in person before the court on the appearance date listed on your citation. (dmv.org)
If you feel strongly that your ticket was issued mistakenly and you would like to file a not guilty plea with the court, your best bet is to hire an attorney. (texas-defensivedriving-courses.com)
A conviction or guilty plea on a sex crime can mean that you have to register as a sex offender for the rest of your life. (stevenmoorelawfirm.com)