>>26507890Elite trainer boxes are not decks. They contain crap like play mats, card sleeves and dice, along with some boosters that contain random cards. You can only really use most cards if you have others to go with them (such as evolution cards or the correct energy), so you'd have to buy dozens of packs before you could build a deck.
To get started, buy a theme deck. These are pre-made decks that work well together (but are generally missing powerhouses) then buy lots of boosters and use the things you get to gradually upgrade your theme deck and eventually make completely new decks.
If you have nobody to play against, use the codes you get in each pack to play the TCG online.
If you have a lot of money and want to play seriously quickly, look up a tournament deck and buy the individual cards on eBay.