Common Land
The amount of common land in each county varies enormously. Cheshire for example has only a few tiny little bits whilst Powys has lots. A friend tells me that any land bordering a canal or road or that is owned by the council and is steeper than a certain gradient is also common land. I have drawn a blank researching this though. It appears the internet does not have all the answers.
You have five rights over common land
So assuming you don’t keep pigs and your local common land doesn’t have a fish pond you have the right to take: fire wood, plants and animals. In practice so few people use common land no one cares what you do. The best use it to graze your goat and of course make hay to feed her during the winter. The proximity of common land might just swing your decision about keeping goats. You can try cultivating common land or planting fruit trees but the trees and the produce is no more yours than it is anybody else’s.