I think the book was to be one of a series, but I only read the first one. It was set in a land with a limited map, like a world within a land, and the people who lived in the land where unaware of the wider world.
There was a red dragon or lizard named Jaz or Baz or Kaz who was funny and the best friend of the human, who I believe was female.
The cover had the lizard-type creature perched on a roadside boulder, with the road winding down a hill and maybe clouds around the edges.
I believe I read it in the 90’s or 00’s