Well first you need a game if you're going the digital route. There are two games available for free download that are about making decks and battling. One is just like the actual Trading Card Game (TCG) only it is in a digital format so you don't get tangible/physical cards. Same cards, same match formats, same everything. That's called TCG Live (Trading Card Game Live). The other is called TCG Pocket (Trading Card Game Pocket). That one is great for daily collecting and playing a quicker version of the TCG or TCG Live matches. Smaller battle decks, quicker matches, only 3 bench spots in a match and the cards themselves are slightly different than the actual cards. That one I play daily. Might I also suggest that you check out the sections here for TCG Live and TCG Pocket? Those are great places to ask questions about the games and interact with other trainers/players. Good luck and welcome to the forums!