Ah, the most popular formats are:
EDH (something something highlander) which is a deck comprised of at least 100 cards with no duplicates and a 'commander' card that starts on the table but out of play that can't be killed permanently (cost just goes up to summon it back).
Standard, which is the most recently released sets of cards.
And Legacy, which is pretty much anything ever released goes.
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I'm guessing it's probably standard or legacy, the only real difference being the time that the cards were released. And it sounds like a standard beatdown playstyle.
Anyway welcome to MTG, I don't really have any advice as I've spent quite a bit of time and $$$ on this game, yet haven't gotten much better at it but still rather enjoy playing.