To make the CPU cars drive around in a track you will need AI nodes. Without AI nodes you can’t have a proper race against the AI.
AI is short for Artificial Intelligence, which means that the computer cars have their own “fake” intelligence. But still, the cars don’t know where to go, and how fast they should go, and when to brake. This is when AI nodes comes in handy. The cars do know how to read the AI node path, which is a part of their intelligence.
AI nodes are nodes in a track, which you can connect to make a complete path. The nodes tell the cars how to drive in that part of the track. With AI nodes you have the exact control over your AI cars, telling them what way to go, let the cars maintain a certain speed, give the cars actions, like: taking the pickup route, using the battery, drive careful under stairs and many more things.
You can find a tutorial for AI Nodes on lean.re-volt.io