For the first scene, add a node called Main to serve as your scene's root. This scene will contain the major parts of the game, starting with the course itself. Start by adding a GridMap node to lay out the course.
Creating the course
GridMaps
GridMap is the 3D equivalent of the TileMap node you used in earlier projects. It allows you to use a collection of meshes (contained in a MeshLibrary) and lay them out in a grid to more quickly design an environment. Because it is 3D, you can stack the meshes in any direction, although for this project, you'll stick to the same plane.