How much experience do you have using After Effects? The thing is, stuff like this is complicated. A tutorial that shows how to do it one way with one shot won't necessarily work for a different shot.
You need to learn:
- The basics of using After Effects (this could take a while - AE is quite complicated)
- Color correction
- Motion Tracking
If you want to convincingly add yourself to a move you need to figure out the distance the original actor was from the camera, match that, match the camera moves and blocking and lighting, learn about rotoscope and layering, learn about motion tracking and camera tracking, probably learn about keying and then start planning the shot.
If you just want to throw yourself in a scene then learn about rotoscoping or keying, put yourself on a separate layer and try and make it look good.