|"Is this all real? Or has this been happening inside my head?"
The topic of this article is of a real-life subject that has been mentioned "in-universe" in a canon source. The Harry Potter Wiki is written from the perspective that all information presented in canon is true (e.g., Hogwarts really exists), and, as such, details contained in this article may differ from real world facts.
When they inadvertently were brought back in time to 1981 by Delphini, wandless and broomless Albus Potter and Scorpius Malfoy walked from the Hogwarts grounds to Aviemore train station. There, they learned it was the day before Lord Voldemort killed James and Lily Potter, and and the two boys journeyed to Godric's Hollow in the West Country to prevent Delphini from changing history.