If you get to done with the Football hall of fame early enough and make it to Cleveland with time to spare you should also check out the Rock and Roll Hall of Fame. You can even get a discount online if you go to both. Both can easily be done in one day. They each take about three to four hours to do and the drive between them is only about 45 min. and the Rock Hall is just up the road from Progressive Field.
That'll be a fun trip! I grew up in Minneapolis and now live in Wisconsin. Are you a beer drinker? If so, definitely check out Lakefront Brewery in Milwaukee, Fulton Brewing in Minneapolis, and Great Lakes Brewery in Cleveland. All have good brews and good atmosphere! If you wander down by the Golden Glove at Target Field, there's some interesting Twins history if that appeals to you.
For parking, here's a handy guide with some $5 lot tips at all the MLB stadiums: http://blog.spothero.com/2016/04/19/2016-mlb-parking-report/
Hope that helps!