Mendix Rapid developer course is based on version
Here's the link for the page which says that.
Hope It helps!
Mendix releases a new version every month. 9.12 dates back 6 months. 9.18 is the current latest release. You can do the course in 9.12.4 in which it was written. This will make sure that the instructions of the course will match your Studio Pro.
To give a more general answer that will age better: each learning path states the version to use in the main screen: