Ivan, i just watched the youtube link you posted, in fact the effect is tricky but simple, i would recomend you start editing the picture you want in photoshop (i will refer from now on to the composition were there is a tree with a bird and a boat in the bakground, its the same process for the rest).
First separate the shape of the tree with the bird from the background, then using the clon tool or wathever tool you u like fill the background so there is no tree, so u have a layer with a clean background and the tree separated in another layer. Then import de psd in after effects. In the composition, place the layers in the timeline, activate the 3d property of both layers (i usually work with the top view and active camera at the same time doing this), you should set the position property of the background layer away from the “tree” layer. create a new camera, select the type of leens that you please or use the default one, and now you should scale the bakground so that it fits the composition, and separate it in the z axis from the tree layer as you please (if its far away, you have to scale higher, and it looses definition). then just play animating the camara along the 3d space to see the effect work.
Andr