Disheveled Cramped Living Space

My family and I moved in with my grandfather who is a postal worker. As you can see, things are pretty messy! We could use a bit of desks, storage, lights, etc. Help would be much appreciated. The lighting in the room isn't so good, and it lacks proper organization. There are no desks and the only table is filled with boxes of things; the house could use a nice modern feel too.