I want to recreate the ICarly Intro.

That specific slip was probably made from a template. While it is possible to track most of the green screens and replace them with video or images you are going to need to break the clip up into about 50 separate comps and do 50 or more tracking jobs. It would take me about a week to complete the project using tracking. Many of the shots would have to be positioned by hand. Trying to do the project using motion tracking would be an incredibly inefficient way to approach the project. The green is something that was added by the person creating this video that they mistakenly thought would make it easier to replace the screens but it actually makes it harder to work with the project. If I had created that project each screen that needed tracking would have a checkerboard pattern. That would make it extremely easy for Mocha or about any other screen tracking software, to track the camera moves. There is no reason to use color keying for any of the screen replacement. It's just a total waste of time. This is a perfect example of a project offered up by an amateur that doesn't really understand production workflows.

On the other hand, recreating the main graphic in illustrator with each element (screen) on a separate layer, importing as a comp, then arranging the entire thing in 3D space adding the 50 or so video source layers and animating the entire project by hand would probably take a little less than a full production day. The project would be extremely complex and frustrating for someone just starting out. It would require a really decent understanding of animating a camera and AE's 3D space. The timing and camera moves also require a good understanding of the basic principals of animation as explained in "The Illusion of Life" by Ollie Johnson and Frank Thomas, that anyone wanting to create motion graphics should buy and study.

I have no idea what level of experience you have so I'm not sure what to suggest but I would start by importing a frame like this one into illustrator to use as a guide to recreate the artwork used in the video, use the video as a timing and camera move guide and build the entire thing from scratch. It will take you about 1/10 the time it would take to do all that tracking.