How do I store data in the CMS?

You don't! 

There is no data store other than for pages and assets. You do have options, however.

NOTE: The CMS isn't really for research and instructional use, should your project be of either of those types. It is used for marketing and information -- with any transactional functions happening externally.

1. Before deciding on your data solution, file a ticket with CMS support and discuss with your unit's web development personnel during the needs gathering phase so you can understand your options within the university's existing, and supported, environments.
   
   
2. There are some ways to get external data into the CMS via XML or JSON, but it requires more advanced development work as there are no built-in components for doing this within Adobe Experience Manager (the back-end of Ensemble). Again, please file a ticket with CMS support and discuss your options with your unit's web development personnel.
   
   
3. The university does still have additional web hosting services, but those aren't managed by CMS folks and you'd need to submit a Service Now ticket to request a hosting instance and information on how to use it. https://vt4help.service-now.com/