All the ismulations used in the courses can be downloaded for you to execute them locally as you say, following the notebooks but executing it localy. You just have to look for the simulation that is launched.
The best way is to see exactly the launch of the unit, and then doing a roscd to know the package name in which that launch is an dthen go to our gits and download that simulation. Then you just have to install the needed dependencies.
ps faux | grep .launch
This will give you the launch used in the unit. For example: bb_8_gazebo main.launch
Then you do:
And it will take you to the package and you can see the parent folder and there fore the gits name: bb8.
Then you go to our public repo and search for that simulation git and download it. And install the dependencies asked for when compiing it with catkin_make-
Hope it helped