Hi,
Sorry for the issues you are having. I can help troubleshoot them with you.
First can you please verify that both The Events Calendar and The Events Calendar Pro are active and both are version 3.9.1
We have this guide for recurring events:
https://theeventscalendar.com/knowledgebase/pro-recurring-events/
That can help you get started and it is best to create a new event for all recurring events and not turn a already published event into a recurring event.
Let me know if you are not see the recurring section.
Thanks