It depends what is available, a shelter could be as simple as leaves piled on top of a simple frame of sticks, it could be a brick built house with central heating & indoor plumbing. How urgently...
Here's what I'd do. Go out and buy a new septic tank (I don't know how much they cost,) and stock it with food and water. Generic brand canned meat is normally the cheapest. Now, if you're going to...