As someone else said, going into a place that is marked clearly with no-guns signage can get you arrested for criminal trespass. Evidently also having a gun in a parking lot of a prohibited place can get you a lesser civil trespass charge, but it's probably an unlikely scenario. Must inform police immediately if pulled over, even if you're a passenger (I think). Can't carry while drinking but you can carry into a place that sells alcohol as long as you're not drinking. Supposedly cops there are not as OC friendly as in Indiana and hassle people more. Can't carry in police stations, universities (illegal by law unless locked in a car or in the process of being locked in a car in the parking lot), churches (unless you have explicit permission from the church), school safety zones (including school activities and everything up to school boundaries) etc...A big one is that you have a duty to retreat before use of deadly force unless you're in your home/car, as far as I understand. Also I hear that Ohio is the only state in the country that still places the burden of proof for self defense on the defendant rather than the prosecution having to prove it wasn't self defense. Hoping that changes soon. Those are all the big differences.
When you say that, does that mean they'll simply ask you to leave or will they straight up arrest you for unlawful carrying of a deadly weapon?