If no Enrollment Periods are showing up on the Enroll Form, you will see a message like this:
The reasons no Enrollment Periods are showing up could be the following:
No Enrollment Periods have been published. By default, newly created or duplicated Enrollment Periods are unpublished. When you are ready for them to be used (show up on the Enroll Form), could you publish them?
Here's how to publish an Enrollment Period: Click the cog icon beside the Enrollment period, then the "eye" icon to publish an enrollment period. When the eye is crossed out, the Enrollment Period is unpublished.
The Enrollment Period may be archived. Archiving does the following to an Enrollment Period:
Removes it from the Enroll Form
Removes it from the Customer Portal
Removes it from the Instructor Portal
Cancels any future Class reminders for enrollments in this Enrollment Period
Cancels any future Auto-Billing events in this Enrollment Period
Historical context of enrollments in this Enrollment Period is preserved
See this support article for more on archiving Enrollment Periods.