Thank you Gemy
The ground on the last show was asphalt. It was a big parking area.
As for the grass, if I remember correctly it was a bit wet in the breed ring and dry and roughish in the main ring (for the best junior in show).
His first show was on carpet though.
From what I have read it is very important for the show puppy to play and run on grass from a very young age in order to familiarize with this terrain. Otherwise it will feel like walking on an unknown surface.
We were fortunate that Sunny grew up in a house with a big garden with grass, where he could play with his siblings and practice trotting with the show lead.
Here in Europe we have many shows held on grass, so it is crucial to teach the puppy to feel comfortable in this kind of surface.