Hi Marcheta,
For contract workspace related data you should be able to find a standard export event Manage -> Administration -> Data Import/Export -> Export tab -> search for word "contract"
And you should see an export event that will read out something similar to export contract workspace header data. This report will give you all the contract workspaces header data I.e. all the fields that you complete while creating a contract workspace. This should give you a starting point for your analysis.
On the enterprise users data, you might need a custom report (contact Ariba support) for last login date, rest of the data can be found in the Enterprise Users data export event.
Regards
Vilas