Bring a copy of the lease, a current copy of their payment ledger, and a copy of the notice to quit that you posted inside their door or sent certified mail. JP court rules may be relaxed a little, but it is still a rules-of-evidence process. you will have to show these things to the judge and the tenant to verify this is what you agreed to. You state your name, your relationship to the property, and your reason for filing suit (violation of lease/non-payment of rent). That's your only reason for being there.
Object to any statement about repairs, poor service, whatever. It is irrelevant, they have to pay to expect anything, including repairs, and have to advise you in writing of a rent strike or other legal means for non-payment. Tell the judge you want possession and back rent. They calculate the rent on a daily basis up through judgement.
Different JPs do it differently, and this is not legal advice. Don't be afraid to say you're nervous and unfamiliar with the process, but stick to your guns and DO NOT interrupt or talk over the judge. His house, his rules.