If you want to defend your charge you plead not guilty.
The usual process then is to try to have the charge withdrawn by police prior to the hearing and there is usually a specific court event for these negotiations.
If that fails then you will appear before a Judge along with the witnesses.
If you win then no conviction is entered against your name.
If you lose - the sentence you receive will be more severe than if you plead guilty earlier.
I've successfully defended charges across the spectrum of criminal cases from domestics to possession of weapons and interfering with motor vehicles.