Hello, first time posting

etc. etc.
I am traveling from Boston to Providence via the MBTA, and from there I need to get to East Greenwich so I can surprise my girlfriend who is running an event there. Unfortunately, I have no car, cannot rent one (18), and know no one around the area. I've visited sites and have come up with nothing. I'd rather not have to rent a bike (for an hour-long bike ride), but that is an obvious (and last option).
I was wondering if any of you people could suggest a way to get to East Greenwich using public transportation? Or at least get down the Warwick area?
Thanks!