From Park Street in the heart of Boston to Kenmore Sq. is 5 T stops taking 12minutes. Ad several more stops through approximately 1 mile to reach BU Agganis Arena.
Roughly 3 miles from the airport to the Back Bay area, maybe 4-5 miles to Fenway. I would recommend taking the T into town instead if a cab if you don't already have a ride; the cab is about $30 (not...