Verona has an old Roman colosseum in Piazza Bra that is still used for opera and concerts in the summer. Right now, there's a huge exhibition of presepi (nativity scenes) from around the world.
There is also an old Roman theater where Shakespeare plays are performed.
Some of the more popular tourist attractions are "made up". There are the Juliet's house (complete with balcony), Romeo's house, and Juliet's tomb all based on Romeo and Juliet. These are representative of the period if they had been real people rather than fictional characters.
Verona has a fairly extensive old town that's authentic with a lot to see. The old castle on the river is now a museum that hosts some interesting exhibitions.
One of the big festivals is the Verona in Love festival in February around Valentine's Day which also has links to the Romeo and Juliet story.
Verona also has a huge wine exhibition and a horse show at the fairgrounds which are worth visiting.
Papa Gnocco - the story is here: http://www.veronissima.com/sito_inglese/html/events_carnival_ing.html