At first the After Effects workspace can seem complicated, but you soon get used to it when you understand the basics.  There are 3 main panels that you will use all the time - the project panel, the timeline panel and the composition panel. 

Project Panel

The project panel is where you import all the files you will use in your project.  They can be all sorts of types of files, including images, sounds, movies and more. 

 
  After Effects doesn't store the files you import into your project - it only makes links to them.  So it is important that you don't change the locations of your original files.

Composition Panel

This shows the current frame of your composition.  You can have more than one composition panel open at the same time.

Timeline Panel

Here you can see all the layers of your compositions and where they are in time in your project.

After Effects has lots of different workspaces designed to make different types of tasks easier.  It's really easy to accidentally 'mess up' the panels on your workspace.  You can fix them up by choosing the Standard workspace, or 'resetting' the Standard workspace .