Night before Christmas
First of all cut all your components in your choice of card.
The main base has only a fold in the middle, The base for the layers to be attached to has a fold line and 4 angled cut lines, these cut lines are for you to slide the layers into add glue them from underneath making a nice neat top on your design.
The back layer is the shortest so it will go the the cut line spaced furthest apart from the others and it is shorter than the other so you will see which one easily enough.
Glue it into place, the next layer is the building scene you have left. So you can attach this one now, then the other 2 are identical so they just go in the front 2 cut line putting them both the same way.
Now attach this layer to the main base layer. Keep if all flat and glue in place, let it all dry before you try and fold it.
Now it's time to put the sleigh and reindeer in place, they just glue to the front of the second fence layer, you can put in in any position you prefer or you can copy the one I did on the image.
Enjoy your project!