In order to log of all operations performed by users, audit setting needs to be enabled for all entities/fields and user access. (refer to the link below on how to enable Auditing in Dynamics 365)
crmbook.powerobjects.com/.../auditing-in-microsoft-dynamics-crm
WARNING: Please be aware that enabling audit for all entities/fields will use up storage capacity pretty quickly. Based on the new storage capacity plan, each environment is only entitled to 2GB of free log capacity and no additional entitlement based on the licence purchased. Additional log storage will incur an additional cost ($10/GB/month US retail price).
docs.microsoft.com/.../capacity-storage
If you are OK with all of those, you can check out the following forum threads on how to getting Audit Record Details from Dynamics 365 to Power BI. It is possible theoretically but that will involve pushing the data into a staging table, transform the data to make it readable by Power BI.
stackoverflow.com/.../getting-audit-record-details-from-dynamics-365-to-power-bi
An alternative solution without all these efforts would be querying the number of records based on createdon and modifiedon of the tables to show how many records are created and updated each day.
The metadata of all Dynamics 365 tables are stored in the tables such as EntityMetadata, AttributeMetadata, etc.
docs.microsoft.com/.../entitymetadata
