One thing that would be handy would be a reference to the robot. IE - although I can use rostopic list to figure out that /scan is the laser scanner, the specs are not obvious. The training robot had a scanner with a ranges array of 0-719, which had a 180 degree sweep. I think that this robot has a scanner with ranges 0-359, which may be a 360 degree sweep, but not sure, and not sure if it’s correct to assume that 0 is forward and 90 is left or right with respect to the robot. This is ROS Basics Real Robot Project.
This kind of reference info (along with API reference material for rospy) would definitely help here.