In Albany, check out the plaza, the banks park, and Seasons for gear. I love that scene there. You can make it up to Burlington, VT the same day in about 3 hours heading north by I-87, Rt 4, Rt 22, Rt 7. Around 1:30 or so through the trip, there's a park in Lake George. It's okay but I have friends in both Albany and Burlington so I skip it.
The Burlington, Vermont area has a few parks to check out, notably the concrete one on the waterfront. It's nice to take some laps and hang out by the lake. I prefer Winooski about 10 minutes away. It's sort of like Great Barrington in Mass or Cherry Park in Long Beach with small boxes and some quarter pipes. I lived in Burlington for 10 years and loved summers there. Swim in the rivers or hike in the day, skate in the late afternoon, then have a few beers or grill food in the evening.
I'm less familiar with Maine, but I assume you'd head east towards Montpelier. There's a fun mini ramp with a spine in the middle in Waterbury, VT at the fire house or whatever. I'd also recommend Warren, VT skatepark, but that seems out of the way for Maine, but it's a concrete DIY that's shaped up pretty well over the past few years. I have no clue what is in Montpelier aside from Mad Taco. Further east around the St. Johnsbury area are a few parks a little out of the way in Lyndonville.
Vermont has a lot of little parks sprinkled in between towns. Southern VT has a good selection too like Manchester, Ludlow, and Rutland. I'm less familiar with that area.
No clue what happens in NH. I just pass through.
I hit Bethel, Paris, Lewiston, and Portland in a single day but it took the entire day. I don't remember much. Lewiston was awesome and Portland was fun too.
I just read your post again. This is too much for 2 days I realize. Leave the weed at home, ask skaters for a plug. From my experiences, it takes longer to enter the US than it does to enter Canada but it was never a huge wait. The experience seemed more friendly entering Canada as well.
Do whatever, make friends, have fun.