Transcode your footage to a supported format. I'm guessing that the footage came from a consumer camera. Use a good DI (digital intermediate) codec like Quicktime JPEG at 90% quality or higher, or any of the other lossless or nearly lossless formats..
Transcoding is converting a file from one format/codec to another format/codec. You can do this in Adobe Media Encoder.
It seems that you really need to begin the basics.
Please, start here to learn After Effects:
Doing so will prevent a lot of frustration.
Hey, how can I change the output file in Adobe encoder? When I try to load it in mocha ae it says c:/users/David/documents corrupt or in unsupported format.
Sent from my iPhone
Read the instructions. AME is seriously easy to use if you read instructions in the help file.