Free range goats on 40 acres

I’m looking at buying a forested 40 acre property in New Hampshire, and I’m in the research phase of acquiring some goats.

The property has pre existing trails, a few small ponds, and is otherwise totally forested. The dream would be to give them an enclosure and let them come and go as they please- letting them free range in the day, and providing them with grain at night. Would that be enough to keep them close? If not, is it feasible to fence off the perimeter of the property, or would it cost a fortune?

Edit: I’m open to breed suggestions too, I’m currently considering the Kiko goat breed. I’m not planning on eating or milking them. Mainly just forest management and entertainment. Possibly interested in selling baby goats down the road.