My question involves criminal law for the state of: Maine

I made a huge mistake and got caught shoplifting $106 worth of clothes from JCPenney. They had me in a back room and gave me a summons for court in a month and a half. I've never done anything like this before, and I'm so scared about what's going to happen. Should I get a lawyer right now or wait until the arraignment to speak with a public defender. Do I plead not guilty or guilty at first? If I plead guilty first, does that mean I'm convicted? What's the likelihood of just getting fined and probation instead of convicted?