Here's a breakdown:
1. Start the game: Begin your adventure in the "Years 1-4" game.
2. Play through "The Escape from Privet Drive": This is the first level in the game, where you control Harry, Ron, and Hermione as they flee from the Dursleys.
3. Complete the level: Once you reach the end of the level and defeat the Dementors, you will unlock the Leaky Cauldron hub area.
After completing the first level, you'll be able to access the Leaky Cauldron and interact with various characters, start new levels, and explore the area.