Hello, it's a pleasure for me to answer your question.
This area you are talking about is very walkable. The Red line train station is 0,3 miles from it right on the crossroads of MAss Ave and Somerville Ave.
You can see a report here about North Cambridge. If you are looking some rentals or homes to buy I'd love to assist you in your search.
PLease see below a walkability report on this area:
Hope my answer helped you.