Randolph and the RMC are usually quite friendly to new folks if they want to participate in local events. Randolph's 200 anniversary is coming up in 2024 so a good time to volunteer as the town is doing a lot of planning. Its a small town with few residents and in order fill all the statutory positions on boards its pretty well takes every official resident to fill the slots. So be prepared to volunteer. Bonus points if you want to be a first responder or even more points for volunteer firefighters.
The RMC is always looking for hike leaders and trail maintainers, no experience or residency required. If you are a member of RMC you should be getting the newsletters and the Randolph Foundation should be sending the winter newsletter. Once the summer rolls around it goes weekly and if you are not in town to pick it up, its available on the Foundation website. If you can make it up for the Randolph Tea (4th of July) that is good kick off event and the RMC annual meeting is another one to try to make. Lots of bonus points if you show up at town meeting in early March.
There are actually quite few books about Randolph and aspects of the town or by local authors, usually they are short run but I think the library has copies. There is supposed to be a book on the distinct architecture of the various summer properties coming out at some point. Doug Mayer formerly from Car Talk has quite a few humor/satire books that he has coauthored over the years, some more successful than others.
The one caveat is you may run into is a northern New England trait that the locals, what few there are in the off season, may not be super friendly, they are usually polite and helpful if you ask, but some folks "from away" get the wrong impression. Many folks "from away"move to the area in the spring to live in the area full time, they have a great summer and fall and usually make it through the holidays but when the dark days roll in in December and the weather cannot make up its mind between late fall and winter, without distractions more than a few folks start to rethink the year round concept a bit. Many times by February they are plotting their escape and as soon as the snow melts the for sale goes up. It happens often enough that some locals just dont want to waste social capital until they are sure the new folks are going to hang around for awhile
If you have winter hobbies involving snow than it may be non issue. Worse case is succumb to the temptation and pick up a few snowmobiles since you have major route in the backyard. Unlike ATVs, snowmobiles are tolerated in town as long as you stick to the trails (conveniently shown on the RMC map) there are ties to many trail systems with hundreds if not thousand of miles accessible.
BTW, NH has a state nursery and sells a lot of native plants. Its long haul down to pick them up but a nice option.