You will be arraigned (asked by the judge if you understand the charges against you) and asked whether you have an attorney to represent you. If you do not, your case will be rescheduled so that you can retain an attorney. If you meet the qualifications for indigent status, the court can appoint the public defender to represent you. You can fight the charge, but showing that you don't smoke marijuana doesn't help you. There are many people who sell the stuff without ever smoking any. If you have never previously been convicted of an offense, the easiest route for you may be to request judicial diversion. It's kind of like a one time deal that will allow you to have the charges dismissed against you and expunged from your record if you successfully comply with the conditions of a one year probationary sentence.
note that offense is called "Unlawful Possession of a Controlled Substance"
The previous answer explains everything quite well, your personal use has no bearing on the necessary elements of proving this case.
Probation is not easy though. When advising a client on the decision to acceptance probation, I always call attention to the effects of being convicted for "someone else's crime." If you are around criminal activity, you can be prosecuted as criminally responsible for the actions of a another. While on probation, you need to stay away from ANY illegal activity, that sometimes means new friends, new job, new school, whatever it takes to keep you out of trouble, Any encounter with law enforcement can jeopardize your probation status, even a traffic citation.