According to the MegaBase, the first chess game Castellvi — Vinoles was played in Valencia, Spain in 1475. By “first chess game,” I mean the first recorded game played under rules similar to those used today. Earlier versions of chess did not have queens and bishops, for example.
Being the first chess game, Castellvi — Vinoles was not very well-played, but that doesn’t matter much. I drift off and try to imagine what life was like over 500 years ago, during the Late Middle Ages and the Renaissance! As a former history major, thoughts like this fascinate me.
I’m not sure castling was allowed in 1475, because the players had opportunities to aim for this most desirable move but did not! I’m almost certain en passant wasn’t in the rules yet; keep that in mind as you play through the game.