Okay, let's take care of a little house-cleaning so everyone's on the same page: it appears as though the police report said damage UNDER $500: that would be criminal trespass, which is a misdemeanor (up to 12 months in custody). When you went to court, however, the charge was amended to a felony criminal damage to property in the second degree because the amount of damage was OVER $500: that's a felony (one year to five years in custody). The change is fairly common in situations like yours: at the time of the incident the officer doesn't know the amount of damage, so he goes with the lesser charge. It's possible that during his investigation, the officer found out from the victim or the insurance company the true nature of the damage (estimates, etc.), and if it's more than $500, the charge gets bumped up to a felony. So now we're on the same page about what's going on with your charge. . . .
You mention twice that you were never read your rights. Did you give anyone a statement? Did you answer any questions? it's a common mistake people make believing the police MUST read them their rights. THIS IS NOT THE CASE. Police officers only have to advise you of your Miranda rights WHEN THEY QUESTION YOU; otherwise, they don't have to tell you anything more than what you've been charged with, and sometimes you won't even get that. If you weren't the subject of interrogation, your Miranda rights don't apply. It's not like TV: an officer will only give you the warning if he plans to ask you questions. Most of them want you to start talking on your own, so they don't ask any questions, hoping you'll start to spill the beans on your own: if you do, it's admissible because whatever you give them wasn't the subject of interrogation. . . .
Hope that answers both of your questions. You really should look into hiring an attorney: most provide free consultations, and there will be many qualified attorneys in your area to obtain good solid information from. Good luck!
Mr. Kilgo is absolutely right regarding your Miranda rights and that it is not unusual for the charges to be amended later in the proceedings. It's also not unusual for you not to have a new court date when you bond out -- you should receive notice in the mail. If you change addresses while out on bond, be sure to notify the clerk of the new address, if they mail it to the old one, it counts whether you actually get it or not and its not an excuse for failing to appear.
One area where the assistance of an attorney would be very helpful to you is in assessing the evidence that the state is using to support its claim of greater damages. An attorney may also be able to help you negotiate a reduction of the charge.
I second Mr. Kilgo's advice, consult an attorney.