All parts of downtown and the North Michigan Avenue are safe. Unless you are extremely adventurous/looking for trouble, any areas that you, as a tourist, would be interested in seeing are safe.

If you want to get tickets to a Cubs game, I suggest looking on Stub Hub, as opposed to Ticketmaster or the Wrigley Field box office. It's a down year, so you'll probably be able to get tickets for less than face value.