Moving clips between After Effects projects is a common task that can be done in a few different ways. The most straightforward way is to simply drag and drop the clips from one project to another. However, there are a few things to keep in mind when doing this.
First, make sure that the two projects are open in the same instance of After Effects. If they are not, the clips will not be able to be dragged and dropped. Second, make sure that the clips are in the same format. If they are not, they may not be able to be imported into the other project.