"Well there's no time for a tour - we have a murderous witch to save the world from…."
-- Scorpius Malfoy (CC4.3)
31 October 1981
Albus Potter and Scorpius Malfoy arrive in Godric’s Hollow. Albus has never visited previously, although his father Harry had offered several times to take him there. Scorpius shows him some highlights and they see his grandparents Lily and James Potter with baby Harry (CC4.3).
The day after the previous event - 31st October 1981 - Albus and Scorpius having travelled from Aviemore in Scotland to Godric's Hollow
This event takes place during the Voldemort Final timeline, as described in the essay "Albus Potter and the lesson in Quantum Mechanics" by Nick Moline.
Scorpius Malfoy gets very excited when he sees Bathilda Bagshot: "Oh my, that’s her. Wow. Squeak. My geekness is a-quivering" (CC4.3).
How Albus and Scorpius get to Godric's Hollow is not explained, the location of the village being a matter of conjecture (West Country and Wales being two alternatives). If they took a train, they would have really needed to have Muggle money. Being underage, they can't use magic outside of school to hide themselves inside train carriages either.
From the Web
Pottermore: Harry Potter and the Cursed Child
The theatre production opened in the West End of London at the Palace Theatre on 30 July 2016, with Sam Clemmett in the role of Albus Potter and Anthony Boyle as Scorpius Malfoy: Harry Potter and the Cursed Child, Parts One and Two