Daughter wants to start collecting. Looking for guidance.

My daughter would like to start collecting Pokémon cards after a bit of influence from her friends. I’m all for it as I was into the show as a kid but focused more on sport cards, so I can appreciate the feel of pulling a special card in a pack.

I don’t think she’s looking to play the game, just make a collection so I’m reaching out to see where we should begin. I just want to be able to guide her a bit when we’re looking for stuff but at the same time I’d like for her to be able to pull something unique that her friends may not have.

Also where is the best place to buy?

Any help is much appreciated.