In the vicinity of Alander, camping is restricted to the Mt. Washington State Forest (MA) backpacking site about 1.5 miles west of park headquarters.
Anyone can stay at the Alander cabin, which is open to whoever shows up, no reservations needed.
Access for both is from park headquarters on the west side of Mt. Washington Rd.
Nearby on the Appalachian Trail (east side of Mt. Washington Rd.) there are several official tent sites and lean-tos. One of the better known camping spots is Sage's Ravine, a quietly spectacular area on the CT-MA border (no fires). From the parking area, it's less than an hour's walk down to the site, which has tent platforms, water and privies.
Another good camp site is Glen Brook, also on the AT. There's a fire ring at the lean-to - which is a charmer - also several tent platforms, water, privy.
Both of these AT parking areas are only a few minutes from the Alander trailhead at Mt. Washington headquarters, though there are other ways to access Alander from NY.
Sunsets from Alander should be very good. You can see the Catskills from there.