I tend to be a fan of Lou Malnati's in terms of deep dish from the standpoint of I think it provides the best all around experience in that both solid pizza and a good restaurant experience. Uno's is tiny and you almost have to go there on an off time. The closest would be on 439 N Wells downtown in the River North area. In the River North area, there's also Farmhouse (beer battered fried Wisconsin cheese curds; http://farmhousechicago.com/menus/) and Boarding House (https://www.tripadvisor.com/Restaurant_Review-g35805-d3708029-Reviews-The_Boarding_House-Chicago_Illinois.html#MAPVIEW).. River North is also the home to the famed restaurants of Rick Bayless; while Frontera Grill is often crowded, casual restaurant Xoco (http://www.rickbayless.com/restaurants/xoco/) is a great way to get a taste without such a wait. River North is also the home of Portillo's (https://www.yelp.com/biz/portillos-hot-dogs-and-barnellis-salad-bowl-chicago) and Doughut Vault (https://www.yelp.com/biz/the-doughnut-vault-chicago, which is open until it sells out for the day.)
Across from Millennium Park on Michigan Ave, Acanto's a good Italian spot (https://www.tripadvisor.com/Restaurant_Review-g35805-d7083948-Reviews-Acanto-Chicago_Illinois.html). Nearby, I also like Wildberry (https://www.tripadvisor.com/Restaurant_Review-g35805-d2407503-Reviews-Wildberry_Pancakes_and_Cafe-Chicago_Illinois.html) a few blocks away. Eataly (https://www.eataly.com/us_en/stores/chicago/) is a lot of fun to browse around and is great for a snack - terrific focaccia bread. That's right off Michigan Ave, so easy stop to tie in if you're going shopping. Also good for a quick bite is Hendrickx (https://www.yelp.com/biz/hendrickx-belgian-bread-crafter-chicago), which is on a side street towards the top end of Michigan Ave. Further North in the Gold Coast is Gibson's (https://www.yelp.com/biz/gibsons-bar-and-steakhouse-chicago, which you see the front of in the FX series, "The League") and Blue Door Kitchen (https://www.yelp.com/biz/blue-door-kitchen-and-garden-chicago-2) among a number of other restaurants.
It is not open on Sunday, but Chicago French Market (https://frenchmarketchicago.com/location/) is a few minutes walk West of your hotel, under the train area at the Ogilvie Transit Center. The newish Revival Food Hall (https://www.revivalfoodhall.com/) is also an easy walk from your hotel. Both of these options provide places not far from your hotel that provide a variety of different options in one place. Some of vendors in these markets have food trucks or restaurants elsewhere in the city as well.
Definitely let me know if you have any other city questions at all.