How could I win or buy one Creg Card.?

I'll gift you one as I'll probably never sell them 1 I think is Creg 2-30 randoms pick a number I'll show it below. if you like it I'll ordinal-ize it later and send it.

I liked. Could be the pack cards organized in a Collection.?

yep I'm still waiting for 1sat alpha's collection feature.

Zoide works, I recommend you create the 3D collection there.
The collection could be mint as airdrop to your own wallet and then distribute it, or mint to sell or mint to auction.
Example:
https://zoide.io/market/collection/929f95e0fd3ec8a292d77ddcd773213419b248413d780db19cf7d1b03ee2e713_0