I'm going to Cleveland soon, too. I'll be there from Aug 22 to Aug 25 (hopefully - it could extend a couple of days longer), but won't be able to do anything outside of my main purpose for being there. This will be my 3rd trip there since April, when my husband had literally life saving surgery there. He's having more surgery - they are going to install a permanent defibrillator this time and, hopefully, it will be the end of his need for medical intervention.
The answers sound so appealing - I wish I had time to go see and do these things.
You could take the Underground Railroad Tour:
There's Woodland Cemetery with many Civil War Soldiers (now on the registry of Historic Places): https://en.wikipedia.org/wiki/Woodland_Cemetery_(Cleveland)
You can stop for lunch in Little Italy: https://www.universitycircle.org/visit/little-italy
There's also the Dunham Tavern, the oldest building in Cleveland: https://www.atlasobscura.com/places/the-dunham-tavern
Case Western Reserve University