My question involves criminal law for the state of: Michigan

A few friends and I were going fishing about a month ago in an old gravel pit. We always went back at night after we got off of work and never noticed any trespassing signs. We ended up going back one day during daylight and didn't even think to look for signs. We drove through an entrance that was through a ditch. Long story short it was posted and we all got tickets. It was posted, signs were on every telephone pole but faded. It was posted though.

Anyways, i've gone through arraignment and told the judge i wanted to plead guilty, he told me it wasn't a good idea and put me down for not guilty. My question is, what happens at the Pretrial date. I have never been in any trouble before and have a clean record. Can anyone give me any advice? I'd like to get away from this with nothing on my record. How many more trials do i have? I just started college so i can't miss too much school.