* Playing through the story mode: As you progress through the story, you'll unlock new cards by winning duels or completing challenges.
* Completing side quests: There are various side quests and mini-games you can complete that reward you with cards.
* Trading with other players: You can trade cards with other players using the game's trading system.
* Using card packs: You can purchase card packs from the game's shop, which contain a random selection of cards.
Important note: The game doesn't have any online features for downloading cards.
If you're looking for ways to expand your card collection in Yu-Gi-Oh! Tag Force 2, focus on completing the game's content, trading with other players, and using card packs.