Does anyone know of a tutorial on how to repeat elements in After Effects?
This is an example:
The elements would animate from left to right/top down.
If it's a shape layer, they have a repeater function built in. So you can create your assets in Illustrator and convert them to shape layers in AE or just draw them in AE yourself.
Read up on shape layers and their powerful operations here: After Effects Help | Shape attributes, paint operations, and path operations for shape layers