Bolzano, Lake Como and Piedmont, Italy HELP

My husband and I be retired by June 2018. We would like to travel to Northern Italy in September 2018 for 3+ weeks. This is what we are thinking with some questions.

Fly into Milan, train to Bolzano. Is the train direct? Can we get off the train and walk to an accommodations? How do we purchase tickets for the cable cars? Are there trains from Bolzano to Lake Como?

Leave Lake Como and rent a car somewhere (help). Go the Piedmont for a week and then Cinque Terre.

Suggestions and help please