Penelope B.
Yelp
I'm used to the farmer's market in Minneapolis, so the Portland market is a little small. However, size is not necessarily an indicator of quality, and this market is high quality. The local vegetables and fruits are lovely and extremely fresh. There's quite a good variety in general and within types - want apples? What kind? Cherry tomatoes? There's a whole selection. Hot peppers? There are a lot of poblanos and padrons, but one or two vendors have a few hotter peppers. Do you want your greens on their own, or perhaps still attached to a beet? Root vegetables, squash, berries, melon, mushrooms, eggplant, beans, garlic... if it grows in Maine and it's legal to sell, you can get it at the market. Local honey, meat, and eggs are available. You can also get homemade pickles, jam, yogurt, cheese, granola bars, bread, soap, yarn, and perhaps most surprisingly, cajeta. The cajeta is delicious.
If you don't have cash, there's a table where you can get tokens with a credit card. They also take SNAP/EBT.
Just forget about going to the grocery store, you don't need to bother with that. Come to the farmers market, get the fresh food from a local farmer, and go home and eat like a god.