You can be caught up rather quickly, it's like magic the gathering or pokemon. You'll put together a team (4 or 5 cards) to fight against an opponent and whether or not you win or lose depends on the stats, level and speed of your "cards" and you'll go back and forth til there's a winner.

There's no stats on the cards right now because that part of the game isn't released yet. It's still in alpha. The game mechanics were released so you should definitely read up on it.

Only 300k "Booster Packs" ($2 each) will be sold during alpha (1.5k total alpha cards) and then the beta cards will be sold during the beta phase, so many think that alpha cards will be more valuable at that time