Matt McSpadden wrote: The obvious would be to cut the trees and sell the lumber, but I'm not sure the trees are big enough to be worth much. The property is also fairly hilly... so even if it was clear cut there is not a lot of places for a flat garden.
If you can clear enough trees to get a 20ft x 20ft sunny patch (even on a slope), then I think you would particularly enjoy having a Well-Watered Garden to start:
https://www.wellwateredgardenproject.org/
Since the trees are small, they should be easier to cut yourself. You could use them for garden crafts or edging along trails, fencing and making pens and shelters, terracing, etc.
Obviously wood heat is one of the most valuable "crops" you can harvest if you have a wood stove and time.
If the trees are a little bigger, you may be able to find a local, mobile sawyer who could mill up some lumber for free. Regardless, definitely spend time discovering the useful trees that are already growing. Also, since you have hills, maybe think about small pond possibilities.
But there is no substitute for sunshine! For food and for morale sake.