How to make gazebo world model?

I’m now trying to make gazebo world using turtlebot3 like below website video.

How should I start this work in gazebo ?
I’m already make new sized real lane track that is different from what I mentioned above.
Using my real track, I wanna make gazebo simulation world.

I hope to hear your advice.

I would recommend you that you download the code of the autorace and just replace the lanes track by your lane track.

If you want to actually create your full Gazebo world, check our Youtube video series about Gazebo, as well as Live Classes #16, #18 and #19


Thank you for your answer.
I will try to create my gazebo world. and hope to share it later.