By design Event Log File are available only through the API, but you can still install manage packages or create your integration to bring the data into the Salesforce user interface.
In Event Log Files, there are some instances where the IP address will display as N/A or blank when a report is scheduled to be sent to users through an automated process, and report names can show up as empty this is because a user name saved the report name, or the report is stored in a user personal report folder.
When enabling Event Log files it will only become available in the future, for example if you get Event Log Files enable today you will be able to get the data moving forward from today, the feature does not have retrograde capabilities it does not allow users to query the data in the past.
CreatedBy.Name and LastModifiedBy.Name field values on EventLogFile object Limits
The queries below will not be able to populate values, because they are not designed to.
SOAP API query:
Select Id,EventType,CreatedDate,CreatedBy.Name,LastModifiedDate,LastModifiedBy.Name FROM EventLogFile
REST API query:
Both queries do not populate value for CreatedBy.Name,LastModifiedBy.Name.