A Magic Junior decks 20 cards, plus 5 Castle cards and 1 Boss card.
Below are 15-card “booster packs” for each color. The packs contain 10 cards, plus 2 single-Castle cards and 1 dual-Castle card. They also contain a child boss or a parent boss card.
Chose two colors you’d like to play with and the packs for each color (you can have a single color deck, just print the same booster twice).
Once you print out the PDF documents, cut out the cards and “Tired” tokens and glue them onto actual Magic cards (tokens or basic lands work fine). Then put them into card sleeves. Shuffle them up and you’re ready to play!