Have fun in my home town!
The CTA's blue line from O'Hare and orange line from Midway are easy economical options, but if you are traveling at night, I would not recommend it. It sounds like you are each getting there alone, and after the daytime crowds thin out, I would not be comfortable, especially from Midway.
In terms of hotels, do you want to be in the middle of the action, which would be more by the river or in a quieter area on the edge? I love the Drake which has a more elegant ambiance but it is not trendy in the least. It is right on Oak Street Beach and you can pick up the the running paths along the beaches right there and many rooms have Lake Michigan views. I realize many would consider this stuffy, but I like the quiet.
The Architectural Boat Tour is a must, but don't book it yet. You would be able to get tickets the day before at this time of year. You need to watch the weather, it snowed there today! And Second City is hilarious, most of the original cast of Saturday Night Live started there and you would recognize many of the alumni pictures.
I am not a fan of a lot of the restaurants in the Michigan Avenue/Downtown area. I think they can be overpriced for what you get and boring. But if it is important your restaurants be nearby, you have a lot of options.
If you are foodies, that whole Fulton Market area is full of award winning restaurants, and a fun vibe with the streets closed off and outdoor seating. There, we love Rose Mary, Monteverde, Ana, and Beatrix. Stephanie Izard , the first female winner of Top Chef, got this area hopping, with her Girl and the Goat and our new obsession Cabra, and she has others. It is worth an Uber ride to try one of these, but get reservations yesterday!
Rick Bayliss's Topolobambo is also good. It won James Beards best restaurant of the year when it opened. It is attached to his Frontera Grill which has similar food but is more reasonably priced. The Kitchen is a pretty spot along the river that has great views, it might be good after your boat tour.
For a different experience, take the 151 bus north and you will get a nice view of Michigan avenue, and the lake and get off at Lincoln Park Zoo. I am not a zoo person, but on southern end, the gardens and ponds there are beautiful, and the zoo is FREE. The Green City Farmer's Market is right there and it is open on Saturday mornings starting in April. It is produce, baked goods and flowers only, no arts & crafts. Nearby, have lunch at the J. Parker on the top of the Lincoln Hotel. https://www.jparkerchicago.com/gallery/
London House's rooftop bar also has killer views, you definitely need reservations.
https://londonhousechicago.com/rooftop/
Enjoy!