Although paper lanterns usually do not come assembled, they are one of the easier things in life to set up. They are available in many sizes, colors, and shapes. You may want to rush into setting it up, but please read a guide like this first, as if you are not careful, you can ruin your lantern. There are a few things to watch out for.
They are most commonly globe-shaped; thus, they are very simple to work with. Since they are packaged flat, they naturally try to revert back to a flat state. Thus, an expander is (usually) provided which will pry the lantern open. You need to get a cord and socket on your own, however, but kits often include a cord and socket. Usually you can find cords of ten or fifteen feet in length. Measure the distance from the outlet to where the lantern will be before buying a cord; if you need more than fifteen feet, you will probably need an extension cord.