You don't need Mario Kart 8 Deluxe's DLC to race the new tracks

The Booster Course Pass isn

Mario Kart 8 Deluxe — Booster Course Pass for the Mario Kart 8 Deluxe game on the Nintendo Switch™ system — Official Site

Mario Kart 8 Deluxe DLC: All Golden Dash and Lucky Cat shortcuts

New Mario Kart 8 DLC Tracks Early

20 Tracks We NEED in the Mario Kart 8 Deluxe DLC

Mario Kart 8 (Video Game) - TV Tropes

Mario Kart 8 Deluxe DLC: All Golden Dash and Lucky Cat shortcuts