System Administrator Responsiblity...any report which lists additions/deletions/changes?

I am a functional GL module lead who is interested in using the "System Administrator" responsibility in Oracle test Instances.  If I add, delete, and/or change anything while using SysAdmin, is there a report that can be run to list those additions, deletions, and/or changes?  If "yes", what is the name of the report?  If "no", is there any query that can be run or any other method used to list additions, deletions, and/or changes?

Thank you, in advance, for your response.

Tom