How can I add a pre-designed path with some obstacles in the Gazebo

Hey all, I'm new to the Gazebo. I'm trying to build the following Gazebo world for the vehicle to follow the path and have obstacle avoidance. My understanding is first of all, add the texture background, here is the lawn. Secondly, add the path/trajectory to the world. Finally, add the construction cones. My question is, how can I add the path in this map.