Using a view to attach fields from a content type to another one
What I would do:

Enable the query preview under Views settings.


Create a new View.
Make sure "Title" is a selected field, and that the titles of both "Scheduled classes" and "Class type" is available in the list.
Add a new relationship, pick the one representing your node-reference. Make it required.
Change the title-fields configuration to select the newly added the relationship.
You should now only have titles from "Class type".


From there on, you likely want to add a contextual filter on a nid so you can pick out "Class type" from a specific "Scheduled class".

I haven't used references in a while. If you get stuck already here, give the same thing a try with entity reference instead, just to see if it plays better together with Views.

Also see Learn Views with NodeOne, episode 11 is specifically about relationships.