Sentencing For Retail Fraud

I had court today for 3rd degree retail fraud (3rd degree if i remember from my class is the lowest). I will not go into detail about how it happened or why it happened. However like the majority of people here, got caught stealing from JC Penny's. Mine was a petty 10 dollar necklace. I had court today and stated guilty. The judge than asks if im sure i want to do that because its a misdemeanor charge, and bean telling me what that entails After saying i understand sir. he asked why im guilty i told him because i did it and have no reason to lie and plead not guilty. He than said he usually throws first offenders in a holding cell for a day or two to teach them a lesson.
Here is what im confused about..... He said he dosnt know anything about me considering this is my first offense so hes going to have me come back april 4th 2008. During that time im supposed to do community service. Does this mean that I am still looking at jail time when i go back with community service hours? Also I received a green peice of paper from him that has his ruling on it. On the Bail line he put 500$. What does this mean?
If anyone at call can help or shed some light on his sentencing i would greatly appreciate it.

~Lost_one~

You need to ask the person who told you these things what he meant.