Those are all what we used to call postcards floating in a dark garage. You've got to make a deep dive into AE's 3D capabilities. Each movie is flat 3D object. You position each object on a stage. A camera flies around the stage. That's about it. But 3D is hard. Really hard. Resist the temptation to use lights.
Each video is on a separate layer and the layers are all 3D. The layers are all either scaled, or better yet, pre rendered at a smaller size and arranged in 3D space.
Because you had to ask I am guessing you are a beginner. Expect to spend 10 to 20 hours learning how to animate in 3D space before you have any success with your project. Expect to spend a lot of time shooting the videos. You will have to figure out how to sync the performances. Playing to a pre-recorded track is a good place to start.
Are you a beginning filmmaker? Doing the animation in After Effects is difficult enough. Shooting and editing the material properly is essential. You must have coherent and cohesive video first.
I suggest you spend a few days acquiring and assembling nine simultaneous video clips into a 3x3 split screen. Then maybe figure out how to switch to full screen for solos and featured passages. Then maybe try to figure out how to wrap your head around a 4x4 matrix of 16 clips.
and the audio is equally important. How will you mix this project? Mixing it before you edit the video would be a huge help.