What part do you not know how to do? Cutting the foreground out? Moving the slips of paper? Creating the slips of paper?
There is nothing in that sample video but a white background, some text animated using text animators, some expressions to help with the bounce effect, and an actor that has been keyed. I think it was probably a greenscreen and not blue because of the light color of the actors hair.
The text animators look to be mostly standard text animation presets that come with After Effects with some modifications.
The expressions for bounce and the rubbery look are advanced techniques requiring a knowledge of expressions and java math - or digging up the proper expressions or animation presets from resources on the internet. You will have to pay for some, but others are free.
The keying is just keying. There are a zillion tutorials on keying in AE.
If you are new to AE, you need to start here: Basic Workflow. If you are not new to AE, tell us what part you are having problems with.
io vorrei creare le animazioni, far spostare la persona e poi inserire le scritte ai suoi fianchi, lo so che il video va girato su un green screen o un blue screen, ma dopo in post produzione come faccio a fare muovere la persona a destra - sinistra e inserire al suo fianco delle scritte come l'effetto della digitazione o a comparsa come al minuto 00:20
Simply animate the position of the footage of the person you have shot on green screen. You may need to use some animated masks on the slips of paper to make them look like they are inserted in the hips (pockets) of the person. If you parent the layers with the paper to the layer with the person when you move the layer with the person the paper will follow.