Lyft and Uber are the main car rideshare companies in Chicago. Also Divvy bikes are available for rental in many places. Chicago Transit Authority (CTA) trains service both O'Hare (Blue line) and Midway (Orange line) airports. It's simple to buy a ticket from the machines at the station. Or download the Ventra app to digitally reload, it works for both the el trains and buses (which run often and are very efficient.)
Chicago is a foodie town! There are great eats of all types of cuisine across the city, but here are some Chi-town classics. Garrett Popcorn (try the cheddar+caramel combo) Italian beef is big here. Al's #1 Italian Beef / Johnnie's Beef / Mr Beef (which inspired 'The Bear') Giordano's / Pequod's / Lou Malnati's for deep dish pizza Coda di Volpe / Robert's Pizza & Dough Company for pizza connoisseurs Jim's Original / Fatso's Last Stand / Devil Dawg's (they have veg options) for hot dogs
Kumiko / The Meadowlark / Koval / Moonflower for cocktails The Hideout / Best Intentions / Consignment Lounge / Skylark for dive bars Pleasant House Pub / The Red Lion Pub / Old Town Ale House for pubs
The Salt Shed / Empty Bottle / Sleeping Village / Thalia Hall for Indie Fitzgerald's / The Green Mill / Hungry Brain for Country, Blues & Jazz
Lake Michigan! You can't miss it. Chicago River architecture river cruise (recommend) Public Art: "The Bean" and Crown Fountain (Millennium Park), Agora (Grant Park), The Picasso (Daley Plaza) If you're at Millenium Park, pop into nearby Chicago Athletic Association and Chicago Cultural Center Iconic Museums: Field Museum, Museum of Science and Industry, The Art Institute, Chicago History Museum, Museum of Contemporary Art For movie buffs: Music Box Theater / Logan Theatre / Alamo Drafthouse The 606 (really nice above-ground walking/biking trail) Gardens: Lincoln Park Conservatory / Garfield Park Conservatory / Chicago Botanical Gardens View the city from above atop Willis Tower or John Hancock Skydeck For the kids: Lincoln Park Zoo, Shedd Aquarium, Nature Museum, Harry Potter Shop, American Girl Place, Maggie Daley Park (Millenium Park)