How do I go about a case with someone who used my name for minor in possession of alcohol?

In my case someone used my name for the citation of minor in possession of alcohol I pleaded not guilty of coarse and I have a pre trial soon. When I was at my first court I told the judge that wasn't me I looked at the citation and I told him that wasn't my signature and if he could have the officer that cited the citation there, he obviously didn't I.d the person and this person i believe is someone who knows me because the signature looked like she was trying hard to make it look like mine. Anyway the judge said he believed me but he couldn't dismiss the charges without the D.A . I don't have money for an attorney so how would I go about this case now? What should I say when I represent myself?