This forum prefers the YGO Pro game rather than this but for those who cant download the game here is a site where you can duel
http://www.duelingnetwork.com/This system is like playing IRL you must know your rulings. As well as all aspects of the game to be successful here. Here you must literally by hand do all your moves. Since this game is not automated. Any questions on such rulings you are able to ask staff to help you.
Though whatever system you are able to use please enjoy the game and have fun.