How to animate

Go to photoshop click file then new and change inches into pixels then click create

 

now you can get a picture for your back and the objects you want to animate try doing a beach and there is an animal in the shadow and when he gets closer to the light the animal will brighten 

ok go to window and select timeline this should allow you to create your animation. click the arrow to you at your option of that layer. If you click the position clock it will add a keyframe and if you drag the red line on the timeline and make another keyframe then move the layer that will make the layer move

opacity is how bright that layer is if it is at 100% then it is at full brightness, but if you click the clock for opacity it will do the same as position but allow you to change the brightness at the beginning and if another keyframe is added and the opacity is different then it will slow change its brightness to that percentage. 

Example: