[Need help] Background Moving after effect

This is very simple and basic. You just need to add a little expression to the position property of the background layer (and make sure, that the layer is a bit larger then the composition, since you are moving it around).

The expression is something like: wiggle(0.2,20);

The first number is the frequency (how often in a second), the second number is the amplitude (how much). Settting frequency to a very low value will result in slow smooth motions. Set the amplitude to the value which fits best.

If you want to learn more, try to figure out how you can use slider controllers to set the parameters of the wiggle directly from the effects panel instead of the expression code editor. This will also give you the ability to animate those parameters and dynamically change the wiggle.

Much fun!

*Martin