Depending on which coast you live, Portland can refer to completely different places. Having been to both, I can say they’re both beautiful but drastically different.
First, Portland, Maine is more of a town than a city. It’s a beautiful coastal town that has some amazing food with fantastic scenery. You can find all sorts of food along the main drag from great seafood (as would be expected) to some great bar eateries and everything in between. Walking around really doesn’t take too long and a leisurely stroll from one end to the other can pretty much be done in a few hours.
I would highly recommend taking a tour of the bay especially on the mail boat run. You can just buy a ticket and the boat goes out to the different islands to drop off mail and anything else. The journey takes 2-3 hours and it’s a great way to see Portland from a different view. You also might meet some locals on the boat and be invited to eat some lobster caught in their own traps!
Probably the biggest food attraction is the lobster roll. Although it is delicious, it is certainly not a cheap sandwich. Having one at the main eateries on the water comes with a great setting but with a high cost. You won’t see many locals there and when I met some locals the following night and told them how much I had paid, they laughed and couldn’t believe it. Everyone sells it so basically paying a fortune for the sandwich really doesn’t make much sense.
If you’re into beer, there are some great craft breweries you can visit as well. Alagash is a little bit of a drive from the city but a only about a 20 minute cab ride. They give you a tour of the brewery as well as offer free tastings. When I called to go, they said that basically anyone who was around could go on the tour at the top of the hour. If you’re more inclined to stay and walk, Shipyard is an easy walk. When I was there, they showed a brief video of the brewing process and then just started pouring samples. If you’re not into specific breweries but want to drink with the locals, try going someplace like the Thirsty Pig. A low key hangout with plenty of food and beer.
For some great seafood (including a great lobster roll) try Eventide Oyster Co. A short walk from Shipyard brewing, it’s a small but popular place and for good reason. The food is reasonably priced overall and and it’s definitely popular so you might have to get there a little early for dinner if you don’t have a reservation.
For Asian flair, try Pai Men and their ramen. It hits the spot and is very good. Again, it’s popular with the locals so lunch may be your best bet. For sushi, try Miyake. I believe both Miyake and Pai Men are owned by the same chef but Miyake is definitely a sushi restaurant. It is a little hidden so finding it can be a bit tricky but it’s definitely worth finding.
For late night eats, try walking around and finding the food trucks. It seems like every night there was some sort of block party set up right outside the bars for people to get their fill of drunk food after last call.
I didn’t experience this first hand but I’ve heard Mainers can be fairly unwelcoming. Everyone I met couldn’t have been nicer but speaking to some Mainers after, they were surprised by my experience. I guess, like many things, YMMV.