The best way to play around with Flexible Data Modeling in CDF is through Templates.
Please be aware of the following before getting started!
Currently, the App Dev Journey team at Cognite is working on a new Schema Service that will replace Templates towards the end of 2022. For more details on the differences between Schema Service and Templates, go here.
There will need to be a migration between Templates and Schema Service in the second half of 2022. The migration will be simple for the data modeling features and querying features as they will be both be using a GraphQL interface. However, moving the data could be a more difficult migration.
Hence we highly recommend continuing with Templates for POCs and early experimentation. You can also productionalize with Templates, but please reach out further clarification around quota and SLAs on this Cognite Hub group.