docs issue at: 快速上手：制作第一个 3D 游戏

**filePath:** [zh/getting-started/first-game/index.md](https://github.com/cocos/cocos-docs/blob/master/versions/3.8/zh/getting-started/first-game/index.md)
**content:** 
1. 创建跑道前，缺少3D切换到2D的步骤
2. 创建跑道时，仅设置了Player节点，Cube节点未说明 [ (0,-1.5,-2), (1,-1.5,-2), (2,-1.5,-2) ]