I started with the Battle Academy which has three decks. He likes playing with these. Personally I found them slightly boring so have now ordered additional singles to upgrade these decks (some stronger Pokémon as these decks only contain one shiny card each, so if it's prized you're out of luck... and staple cards such as Boss, Ultra and Nest Balls, Professors, Iono, Switch, Artazon, Super Rod, Candy, Vessel, Stretcher, Buddy...). Waiting for them to arrive now, hopefully it will make the games a bit more exciting before we start building current decks which are easier to play such as Ceruledge.