To register online in Massachusetts:
Requirements: You may submit an application to register or pre-register to vote in Massachusetts if:
Though you must be 18 years old in order to vote, you may pre-register to vote once you are 16 years old. If you are 16 or 17 years old, you may submit a voter registration form to your local election official, who will then place your name on the list of pre-registrants. You will receive a pre-registration notice by mail, confirming receipt of your application. Pre-registration may be done online, by mail, or in person at any voter registration location.
Will Voting affect Students:
Where, When and How to vote in your state. (https://866ourvote.org/states/)
Federal Voting Information Page: Are you a resident of another State? Do you need to know where to vote? This Federal page provides a wealth of voting information including registration and voting locations.