To check if the Courses was created you should chose 'GET /odata/v2/Courses/IncludeNotCreated()',
add 'ProvisioningProgress' value.
If the Courses was successfully created you will see: "ProvisioningProgress": null.
In other case you should wait for some time (about 5 minutes) and check again.
If the Courses was failed you will see the next: