Sites like ModdingWay or FIFA Infinity provide unofficial squad files to keep rosters up to date for recent seasons.

Since the game is considered "legacy" software, your best legal options include:

The official World Cup free trial and demo versions are no longer active. Where to Legally Find It

Some users turn to communities like r/abandonware for archived versions of games that are no longer available for purchase. System Requirements & Performance

EA Sports has delisted older FIFA titles. You can generally no longer purchase it directly from the EA App (formerly Origin).