you will see a well-known restaurant called Stetson's Chop House and Bar serving both steak and seafood dishes with live entertainment every night except Sunday, I believe. Business attire or business casual will be ok for dinners. No rental car is really needed unless you want to get out of town. The valet parking is like from $28 to $48 per night depending on which hotel you stay so it is not worthy it. You will have Art Institute nearby, Navy Pier, the Field Museum, Hancock Observatory, etc.... Eat something you don't have in the West Coast! The weather in May in Chicago is one of the best you can have for the area, better than May in SF.
After your Chicago visit, you may switch your ID from Parisparis to Chicagochicago.
Welcome to Chicago from an EX resident.