I apologize I didn't see this before now, was very busy the last several days.
For anyone reading this in the future, there's really not much to DO near PWM except a shopping mall, though there are some decent restaurants fairly close - Sea Dog Brewing is very good. But almost nothing is walking distance of PWM, you'd have to take a cab/Uber/etc.
Depending on exactly how much time you have, you could Uber to the Old Port of Portland and walk around there, there are great shops, eateries, etc.