Shoplifting and whether or not to plead guilty?

I was very foolish, decided to shop lift with a buddy for the first time and I got caught. We were arrested and because of our civility we were given a Theft of 3rd Degree (which I think he said was a misdemeanor and not a felony?) by the officer instead of a felony, we didnt spend time in jail (I'm 18). I have an arrangement court hearing tomorrow and am unsure what to expect and what to plead really. I believe I should have an attorney, but I dont really know. I heard of something called deferment, where for 6 months they put the case on hold, and if I'm on good behavior they will drop the case? How can I plead for this? If I plead guilty, can I still get this? Is there any advantage to pleading non-guilty now? Will I lose that deferment option? How will any of this look for when I apply to jobs? I truly appreciate any and all help I can get!