The first set of MTG was released in 1993 by Richard Garfield and a few friends on a shoestring budget
Oh, and it's also a card that Magic's Head Designer Mark Rosewater has called a mistake in his personal blog, so if the next part gets complicated, maybe that's why
To play it, youll exile a card in order to trigger its Harness ability, which essentially brings a creature card back from your Graveyard every turn
If you're starting out, you likely will not touch Legacy any time soon, if ever
There are two cycles of four cards in the set
There are lots of MTG commanders that let you cheat equip costs (in fact Captain America, First Avenger does this too), and the go-to equipment here are things like Colossus Hammer