Pokemon cards opening?

I would like to know if anyone here is familiar with Pokemon cards, so many people put out such openings on Youtube and Twitch. I would like to know where I can buy such boosters, because I can't find anything about them, and on which page it says which card can be the best in the booster.

Can be found in almost every miller's toy department

Almost everywhere there are toys.

Oh, there can also be rare cards included? Only thought about certain ones that you can buy from abroad or something. And then where could I see the prices?

You can buy Cardbuddys, Cardmarket and ebay but you have to pay attention to the seller (on CM and ebay)

otherwise you can buy booster through PokeRev that he opens and sends them to you

and on which side it says which card can be the best in the booster

that's nowhere right, you know that when you're inside

https://www.cardmarket.com/de/Pokemon

I know PokeRev.