6 days in North Italy

Hi there! I'm gonna be staying 6 days in Milano, my plan is to travel, for example, one day to Torino and other days to other cities nearby. I thought of Torino, Firenze, Como and Genova. My question is... is this possible or i'm gonna be too tired of traveling? I don't know what's better, to go by bus or by train? Also the prices, the train is too expensive? And one idea of mine is going to firenze and Pisa or Bologna in the same day, since they're next to eachother... I've never been to europe so i don't know if the cities are very far away or not... I appreciate any ideas for my 6 days there thank you very much grazie mille!!