You need to retain an attorney willing to take an aggressive approach to defending this case. You need an attorney that is going to competently and completely investigate the case including figuring out whether there was an dash cam video/audio from the police car and interviewing the passenger. The first thing is figuring out whether there are legal issues with your case. If not then it is essential to prepare this case for trial and try to put pressure on the state to get a favorable resolution. From your introduction you are seeking to have a jury of your peers decide the case. If that's what you want its essential that you seek out the assistance of an attorney that is willing and capable to do that. An attorney that will do a good job in taking your case to trial will not be cheap. There is a lot of work involved in being able to competently and aggressively defend a person accused of a crime against the government. Best of luck and don't talk to anyone about your case, especially the police.
You need to have an experienced criminal defense lawyer to represent you. Merely being present in a location where marijuana is found is not enough to sustain a conviction. A lawyer working on your behalf will get copies of all police reports, witness statements, police car video (if one exists), and any other evidence to help combat this allegation made against you.
A marijuana conviction could affect your future educational opportunities, future employment, and your driving privileges. Sometimes in life you only get 1 opportunity to obtain the right result. HIre a lawyer immediately.
The best way to fight is to go to trial and win. The officer had probable cause to believe that the marijuana found was your marijuana because of your proximity to it, but that's not proof beyond a reasonable doubt. Winning your case depends on what the witnesses say at trial. If you and the passenger both testify that the marijuana wasn't your marijuana, that might be enough evidence to create a reasonable doubt in the jurors' minds.
Please note that this answer does not constitute legal advice. It is merely intended to provide general information to aid the poster in finding answers to the problem posed. This answer does not create an attorney-client relationship. In most cases, it is best to contact an attorney directly to find answers to your problems.